Examples with solutions for Standard Representation: Transition between different representations of a function

Exercise #1

Find the standard representation of the following function:

f(x)=(x3)2+x f(x)=(x-3)^2+x

Video Solution

Step-by-Step Solution

To solve this problem, we'll perform these steps:

  • Expand (x3)2(x-3)^2 using the formula for a square:
    (x3)2=x22×x×3+32=x26x+9(x-3)^2 = x^2 - 2 \times x \times 3 + 3^2 = x^2 - 6x + 9
  • Add the x x from f(x)=(x3)2+x f(x) = (x-3)^2 + x to the expanded terms:
    x26x+9+x x^2 - 6x + 9 + x
  • Combine like terms:
    x26x+x+9=x25x+9 x^2 - 6x + x + 9 = x^2 - 5x + 9

Therefore, the standard form of the function f(x) f(x) is f(x)=x25x+9 f(x) = x^2 - 5x + 9 .

Thus, the correct choice is Choice 3.

Answer

f(x)=x25x+9 f(x)=x^2-5x+9

Exercise #2

Find the standard representation of the following function

f(x)=(x2)(x+5) f(x)=(x-2)(x+5)

Video Solution

Step-by-Step Solution

We will begin by using the distributive property in order to expand the following expression.

(a+1)⋆(b+2) = ab+2a+b+2

We will then proceed to insert the known values into the equation and solve as follows:

(x-2)(x+5) =

x²-2x+5x+-2*5=

x²+3x-10

And that's the solution!

Answer

f(x)+x2+3x10 f(x)+x^2+3x-10

Exercise #3

Find the standard representation of the following function

f(x)=(x6)(x2) f(x)=(x-6)(x-2)

Video Solution

Step-by-Step Solution

To find the standard representation of the quadratic function f(x)=(x6)(x2) f(x) = (x - 6)(x - 2) , follow these steps:

  • Step 1: Apply the FOIL method to expand the expression.
    - First: Multiply the first terms: x×x=x2 x \times x = x^2 .
    - Outside: Multiply the outer terms: x×(2)=2x x \times (-2) = -2x .
    - Inside: Multiply the inner terms: (6)×x=6x (-6) \times x = -6x .
    - Last: Multiply the last terms: (6)×(2)=12 (-6) \times (-2) = 12 .
  • Step 2: Combine the results from the FOIL method.
    - Combine all the expanded terms: x22x6x+12 x^2 - 2x - 6x + 12 .
  • Step 3: Simplify by combining like terms.
    - Combine the x x -terms: 2x6x=8x -2x - 6x = -8x .
    - The expanded and simplified form is: f(x)=x28x+12 f(x) = x^2 - 8x + 12 .

By expanding and simplifying the given product, we have converted it to its standard form. Therefore, the standard representation of the function is f(x)=x28x+12 f(x) = x^2 - 8x + 12 .

The correct choice from the provided options is choice 2: f(x)=x28x+12 f(x) = x^2 - 8x + 12 .

Answer

f(x)=x28x+12 f(x)=x^2-8x+12

Exercise #4

Find the standard representation of the following function

f(x)=(x+2)(x4) f(x)=(x+2)(x-4)

Video Solution

Step-by-Step Solution

To find the standard representation of the quadratic function given by f(x)=(x+2)(x4) f(x) = (x+2)(x-4) , we will expand the expression using the distributive property, commonly known as the FOIL method (First, Outer, Inner, Last):

  • First: Multiply the first terms in each binomial: xx=x2 x \cdot x = x^2 .
  • Outer: Multiply the outer terms in the binomials: x(4)=4x x \cdot (-4) = -4x .
  • Inner: Multiply the inner terms: 2x=2x 2 \cdot x = 2x .
  • Last: Multiply the last terms in each binomial: 2(4)=8 2 \cdot (-4) = -8 .

Now, let's combine these results:

The expression becomes x24x+2x8 x^2 - 4x + 2x - 8 .

Next, we combine like terms:

The terms involving x x are 4x+2x -4x + 2x , which simplifies to 2x -2x .

Thus, the expression simplifies to: f(x)=x22x8 f(x) = x^2 - 2x - 8

Upon comparing this result to the provided choices, we find that it matches choice 3.

Therefore, the standard representation of the function is f(x)=x22x8 f(x) = x^2 - 2x - 8 .

Answer

f(x)=x22x8 f(x)=x^2-2x-8

Exercise #5

Find the standard representation of the following function

f(x)=3x(x+4) f(x)=3x(x+4)

Video Solution

Step-by-Step Solution

To find the standard representation of the quadratic function f(x)=3x(x+4) f(x) = 3x(x + 4) , follow these steps:

  • Step 1: Apply the distributive property to expand the expression x(x+4) x(x + 4) .
    Using this property, we have:
    x(x+4)=xx+x4=x2+4x x(x + 4) = x \cdot x + x \cdot 4 = x^2 + 4x .
  • Step 2: Multiply each term by the coefficient outside the parenthesis, which is 3.
    This gives us:
    3(x2+4x)=3x2+34x 3(x^2 + 4x) = 3 \cdot x^2 + 3 \cdot 4x .
  • Step 3: Simplify by performing the multiplication.
    3x2+12x 3x^2 + 12x .

Therefore, the standard representation of the function is f(x)=3x2+12x f(x) = 3x^2 + 12x . This matches choice 3 in the provided answers.

Answer

f(x)=3x2+12x f(x)=3x^2+12x

Exercise #6

Find the standard representation of the following function

f(x)=x(x8) f(x)=-x(x-8)

Video Solution

Step-by-Step Solution

To solve this problem, we'll convert the given function from its factored form to the standard form using the distributive property. The given function is f(x)=x(x8) f(x) = -x(x - 8) .

Let's go through the necessary steps:

  • Step 1: Apply the distributive property to expand the expression.
    f(x)=x(x8)=xx+(x)(8) f(x) = -x(x - 8) = -x \cdot x + (-x) \cdot (-8)
  • Step 2: Simplify each term.
    xx=x2-x \cdot x = -x^2 and (x)(8)=+8x(-x) \cdot (-8) = +8x.
  • Step 3: Combine the terms to express f(x) f(x) in standard form:
    f(x)=x2+8x f(x) = -x^2 + 8x .

Therefore, the standard representation of the function is f(x)=x2+8x f(x) = -x^2 + 8x .

Comparing this result to the multiple-choice options, we can see that the correct choice is option 3: f(x)=x2+8x f(x)=-x^2+8x .

Answer

f(x)=x2+8x f(x)=-x^2+8x

Exercise #7

Find the standard representation of the following function

f(x)=(2x+1)21 f(x)=(2x+1)^2-1

Video Solution

Step-by-Step Solution

To convert f(x)=(2x+1)21 f(x) = (2x+1)^2 - 1 into its standard quadratic form, we need to expand (2x+1)2 (2x+1)^2 first and then adjust for the subtraction of 1.

The expansion is carried out using the binomial expansion formula:

(2x+1)2=(2x)2+2(2x)(1)+12(2x + 1)^2 = (2x)^2 + 2(2x)(1) + 1^2.

Calculating each term gives:

  • (2x)2=4x2(2x)^2 = 4x^2
  • 2(2x)(1)=4x2(2x)(1) = 4x
  • 12=11^2 = 1

Combining these, we obtain:

(2x+1)2=4x2+4x+1(2x + 1)^2 = 4x^2 + 4x + 1

Now, substituting back into the original equation:

f(x)=(2x+1)21=(4x2+4x+1)1f(x) = (2x+1)^2 - 1 = (4x^2 + 4x + 1) - 1

Subtracting 1 from the constant term, we get:

f(x)=4x2+4x+11=4x2+4xf(x) = 4x^2 + 4x + 1 - 1 = 4x^2 + 4x

Therefore, the standard form representation of the function is f(x)=4x2+4x f(x) = 4x^2 + 4x .

Answer

f(x)=4x2+4x f(x)=4x^2+4x

Exercise #8

Find the standard representation of the following function

f(x)=(x+1)2+3 f(x)=(-x+1)^2+3

Video Solution

Step-by-Step Solution

To convert the function f(x)=(x+1)2+3 f(x) = (-x + 1)^2 + 3 to its standard form, follow these steps:

Step 1: Expand the binomial (x+1)2(-x + 1)^2.
(x+1)2=(x)2+2(x)(1)+12 (-x + 1)^2 = (-x)^2 + 2(-x)(1) + 1^2

This simplifies to:
(x)2=x2 (-x)^2 = x^2
2(x)(1)=2x 2(-x)(1) = -2x
12=1 1^2 = 1

Combining these terms gives:
(x+1)2=x22x+1 (-x + 1)^2 = x^2 - 2x + 1

Step 2: Add the constant term +3+3 to the expanded form:
f(x)=(x22x+1)+3 f(x) = (x^2 - 2x + 1) + 3

Step 3: Simplify the expression:
f(x)=x22x+1+3=x22x+4 f(x) = x^2 - 2x + 1 + 3 = x^2 - 2x + 4

Thus, the standard representation of the function is f(x)=x22x+4 f(x) = x^2 - 2x + 4 .

Answer

f(x)=x22x+4 f(x)=x^2-2x+4

Exercise #9

Find the standard representation of the following function

f(x)=(x+4)216 f(x)=(x+4)^2-16

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Expand (x+4)2(x + 4)^2 using the formula (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2.
  • Step 2: Simplify the expression by subtracting 16 from the expanded result.
  • Step 3: Write the simplified expression in the standard form.

Now, let's work through each step:
Step 1: Start with the expression given in the problem:
(x+4)2=x2+2x4+42 (x + 4)^2 = x^2 + 2 \cdot x \cdot 4 + 4^2 .

This results in:
x2+8x+16 x^2 + 8x + 16 .

Step 2: Subtract 16 from the expanded expression:
x2+8x+1616=x2+8x x^2 + 8x + 16 - 16 = x^2 + 8x .

Step 3: The standard form of the expression is now:
f(x)=x2+8x f(x) = x^2 + 8x .

Therefore, the standard representation of the function is f(x)=x2+8x f(x) = x^2 + 8x .

Answer

f(x)=x2+8x f(x)=x^2+8x

Exercise #10

Find the standard representation of the following function

f(x)=(x2)2+3 f(x)=(x-2)^2+3

Video Solution

Step-by-Step Solution

To convert the function from vertex form to standard form, follow these steps:

  • Step 1: Identify the vertex form - f(x)=(x2)2+3 f(x) = (x-2)^2 + 3 . The terms inside the parentheses represent a perfect square trinomial.
  • Step 2: Expand the square. Recall: (ab)2=a22ab+b2 (a-b)^2 = a^2 - 2ab + b^2 . Here, a=x a = x and b=2 b = 2 .
  • Step 3: Expand (x2)2(x-2)^2:
    (x2)2=x22x2+22=x24x+4 (x-2)^2 = x^2 - 2 \cdot x \cdot 2 + 2^2 = x^2 - 4x + 4 .
  • Step 4: Add the constant from the original function:
    f(x)=(x24x+4)+3=x24x+7 f(x) = (x^2 - 4x + 4) + 3 = x^2 - 4x + 7 .

After expanding and simplifying, we find that f(x)=x24x+7 f(x) = x^2 - 4x + 7 is the standard form of the function.

Therefore, the correct choice that matches this solution is choice 3, which is f(x)=x24x+7 f(x) = x^2 - 4x + 7 .

Answer

f(x)=x24x+7 f(x)=x^2-4x+7

Exercise #11

Find the standard representation of the following function

f(x)=(x5)210 f(x)=(x-5)^2-10

Video Solution

Step-by-Step Solution

To convert the quadratic function from vertex form to standard form, execute the following steps:

  • Step 1: Begin with the given vertex form f(x)=(x5)210 f(x) = (x-5)^2 - 10 .
  • Step 2: Expand (x5)2 (x-5)^2 using the formula (ab)2=a22ab+b2 (a-b)^2 = a^2 - 2ab + b^2 , which results in:

(x5)2=x22x5+52=x210x+25(x-5)^2 = x^2 - 2 \cdot x \cdot 5 + 5^2 = x^2 - 10x + 25.

  • Step 3: Replace the expanded form into the original function:

f(x)=x210x+2510f(x) = x^2 - 10x + 25 - 10.

  • Step 4: Combine like terms:

f(x)=x210x+15f(x) = x^2 - 10x + 15.

Therefore, the standard form of the function is f(x)=x210x+15 f(x) = x^2 - 10x + 15 .

Comparing with the given choices, the correct option is:

Choice 2: f(x)=x210x+15 f(x) = x^2 - 10x + 15

Answer

f(x)=x210x+15 f(x)=x^2-10x+15

Exercise #12

Find the standard representation of the following function

f(x)=(x+5)2+3 f(x)=(x+5)^2+3

Video Solution

Step-by-Step Solution

To convert the given quadratic function into its standard form, follow these steps:

  • Step 1: Expand the Binomial
    We begin with the function in vertex form: f(x)=(x+5)2+3 f(x) = (x + 5)^2 + 3 . The expression (x+5)2(x + 5)^2 can be expanded using the binomial theorem: (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2.

  • Step 2: Apply the Expansion Formula
    Let a=x a = x and b=5 b = 5 . Therefore, (x+5)2=x2+2×x×5+52=x2+10x+25(x + 5)^2 = x^2 + 2 \times x \times 5 + 5^2 = x^2 + 10x + 25.

  • Step 3: Add the Constant
    Now, add the constant 3 to this expanded result: x2+10x+25+3=x2+10x+28 x^2 + 10x + 25 + 3 = x^2 + 10x + 28 .

Thus, the standard representation of the function is f(x)=x2+10x+28 f(x) = x^2 + 10x + 28 .

Given the choices, the correct answer is f(x)=x2+10x+28 f(x) = x^2 + 10x + 28 , which matches choice 2.

Answer

f(x)=x2+10x+28 f(x)=x^2+10x+28

Exercise #13

Find the standard representation of the following function

f(x)=(x+1)(x1) f(x)=(x+1)(x-1)

Video Solution

Step-by-Step Solution

To solve this problem and find the standard representation of the function f(x)=(x+1)(x1) f(x) = (x+1)(x-1) , we will expand the product using the distributive property, often recalled as FOIL (First, Outer, Inner, Last) for the product of two binomials.

Let's proceed step-by-step:

  • Step 1: Apply the distributive property:
    f(x)=(x+1)(x1) f(x) = (x+1)(x-1) would become:
  • First terms: xx=x2 x \cdot x = x^2
  • Outer terms: x(1)=x x \cdot (-1) = -x
  • Inner terms: 1x=x 1 \cdot x = x
  • Last terms: 1(1)=1 1 \cdot (-1) = -1

Step 2: Combine all the terms obtained from the FOIL method:
x2x+x1 x^2 - x + x - 1

Step 3: Simplify the expression by combining like terms:
The terms x-x and xx cancel each other out, simplifying to:
f(x)=x21 f(x) = x^2 - 1

Thus, the standard representation of the function is f(x)=x21 f(x) = x^2 - 1 .

Answer

f(x)=x21 f(x)=x^2-1

Exercise #14

Find the standard representation of the following function

f(x)=(2x+1)(x2) f(x)=(2x+1)(x-2)

Video Solution

Step-by-Step Solution

To find the standard representation of the function f(x)=(2x+1)(x2) f(x) = (2x + 1)(x - 2) , we'll follow these steps to expand and simplify the expression:

  • Step 1: Distribute each term of the first binomial over each term of the second binomial using the FOIL method.
  • Step 2: Combine like terms to express the function in standard quadratic form.

Now, let's expand the expression:
1. Multiply the first terms: 2xx=2x2 2x \cdot x = 2x^2
2. Multiply the outer terms: 2x(2)=4x 2x \cdot (-2) = -4x
3. Multiply the inner terms: 1x=x 1 \cdot x = x
4. Multiply the last terms: 1(2)=2 1 \cdot (-2) = -2

Next, we combine these results:
- The 2x2 2x^2 term remains as is.
- Add the linear terms: 4x+x=3x -4x + x = -3x
- The constant term is 2-2.

Thus, the expanded and simplified form of the function is:
f(x)=2x23x2 f(x) = 2x^2 - 3x - 2

The final expression in standard form is f(x)=2x23x2 f(x) = 2x^2 - 3x - 2 .

Answer

f(x)=2x23x2 f(x)=2x^2-3x-2

Exercise #15

Find the standard representation of the following function

f(x)=(x+3)(x4) f(x)=(x+3)(-x-4)

Video Solution

Step-by-Step Solution

To find the standard form of the given quadratic function f(x)=(x+3)(x4) f(x) = (x+3)(-x-4) , we will expand it using the distributive property.

Step 1: Expand the product.
Using the distributive property (or FOIL method):

f(x)=(x+3)(x4) f(x) = (x+3)(-x-4)

Apply distribution:
First: xx=x2 x \cdot -x = -x^2
Outside: x4=4x x \cdot -4 = -4x
Inside: 3x=3x 3 \cdot -x = -3x
Last: 34=12 3 \cdot -4 = -12

Step 2: Combine all terms together:

f(x)=x24x3x12 f(x) = -x^2 - 4x - 3x - 12

Step 3: Simplify by combining like terms:
Combine the x x terms:

f(x)=x27x12 f(x) = -x^2 - 7x - 12

Therefore, the standard representation of the function is f(x)=x27x12 f(x) = -x^2 - 7x - 12 .

The correct choice from the given options is choice 4.

f(x)=x27x12 f(x)=-x^2-7x-12

Answer

f(x)=x27x12 f(x)=-x^2-7x-12

Exercise #16

Find the representation of the product of the following function

f(x)=x27x+12 f(x)=x^2-7x+12

Video Solution

Step-by-Step Solution

To solve the problem of finding the product (factored) representation of the quadratic function f(x)=x27x+12 f(x) = x^2 - 7x + 12 , we proceed as follows:

  • Step 1: Identify the function, which is f(x)=x27x+12 f(x) = x^2 - 7x + 12 .
  • Step 2: We need to factor this quadratic expression. We're looking for two numbers whose product is 12 and whose sum is -7.
  • Step 3: The factor pairs of 12 are (1,12)(1, 12), (2,6)(2, 6), (3,4)(3, 4), including negative pairs because the sum must be negative.
  • Step 4: Consider the pair (3,4)(-3, -4). The product (3)×(4)(-3) \times (-4) equals 12, and the sum (3)+(4)(-3) + (-4) equals -7.

Therefore, the factors of the quadratic expression are x3 x - 3 and x4 x - 4 . This implies that the function f(x) f(x) can be expressed in product form as:

f(x)=(x3)(x4) f(x) = (x - 3)(x - 4)

This means the correct factorization is (x3)(x4)(x - 3)(x - 4), which corresponds to choice 3 from the given options.

Thus, the representation of the product of the function is (x3)(x4) (x - 3)(x - 4) .

Answer

(x3)(x4) (x-3)(x-4)

Exercise #17

Find the representation of the product of the following function

f(x)=x22x3 f(x)=x^2-2x-3

Video Solution

Step-by-Step Solution

The problem requires finding the product representation of the quadratic function f(x)=x22x3 f(x) = x^2 - 2x - 3 .

Let's execute the factorization of the quadratic equation:

  • The standard form for the function is f(x)=ax2+bx+c f(x) = ax^2 + bx + c . Here, a=1 a = 1 , b=2 b = -2 , c=3 c = -3 .
  • We seek two numbers that multiply to c=3 c = -3 and sum to b=2 b = -2 .
  • Checking possible integer pairs: (3,1)(-3, 1) can accomplish this, since 3×1=3-3 \times 1 = -3 and 3+1=2-3 + 1 = -2.
  • The factorization becomes f(x)=(x3)(x+1) f(x) = (x - 3)(x + 1) .

To verify, we can expand the binomials:

(x3)(x+1)=x2+x3x3=x22x3(x - 3)(x + 1) = x^2 + x - 3x - 3 = x^2 - 2x - 3.

This matches the original polynomial, confirming the product representation is correct.

In conclusion, the factorization or product representation of the given quadratic function is (x3)(x+1)\mathbf{(x-3)(x+1)}.

Answer

(x3)(x+1) (x-3)(x+1)

Exercise #18

Find the representation of the product of the following function

f(x)=x23x18 f(x)=x^2-3x-18

Video Solution

Step-by-Step Solution

To solve the problem of factoring the quadratic expression f(x)=x23x18 f(x) = x^2 - 3x - 18 , we will use the following method:

  • Step 1: Identify and understand the quadratic expression, which is given in standard form: ax2+bx+c ax^2 + bx + c . For this expression, a=1 a = 1 , b=3 b = -3 , and c=18 c = -18 .
  • Step 2: Compute the product of a a and c c , which yields 1(18)=18 1 \cdot (-18) = -18 . We need to find two numbers whose product is 18-18 and whose sum is 3-3.
  • Step 3: Look for pairs of factors of 18-18: - 1,181, -18 - 1,18-1, 18 - 2,92, -9 - 2,9-2, 9 - 3,63, -6 - 3,6-3, 6
  • Among these, the pair (3,6) (3, -6) adds up to 3-3 and multiplies to 18-18.

  • Step 4: Rewrite the quadratic expression using these numbers to represent the middle term:
    x23x18=x2+3x6x18 x^2 - 3x - 18 = x^2 + 3x - 6x - 18 .
  • Step 5: Group the terms to facilitate factoring:
    (x2+3x)+(6x18) (x^2 + 3x) + (-6x - 18) .
  • Step 6: Factor out the common factors in each grouped terms:
    x(x+3)6(x+3) x(x + 3) - 6(x + 3) .
  • Step 7: Factor out the common binomial:
    (x6)(x+3)(x - 6)(x + 3).

Therefore, the factorized form of the quadratic function f(x)=x23x18 f(x) = x^2 - 3x - 18 is (x6)(x+3) (x - 6)(x + 3) .

Answer

(x6)(x+3) (x-6)(x+3)

Exercise #19

Find the representation of the product of the following function

f(x)=x2+x2 f(x)=x^2+x-2

Video Solution

Step-by-Step Solution

To determine the product representation of f(x)=x2+x2 f(x) = x^2 + x - 2 , we can factor the quadratic equation by following these steps:

  • Step 1: Identify the product ac=1×(2)=2 ac = 1 \times (-2) = -2 and sum b=1 b = 1 .
  • Step 2: Find two numbers that multiply to 2-2 and add to 11. These numbers are 22 and 1-1.
  • Step 3: Rewrite the middle term using these numbers: x2+2x1x2 x^2 + 2x - 1x - 2 .
  • Step 4: Factor by grouping:
    - Group x2+2x x^2 + 2x and 1x2-1x - 2 as separate pairs:
    - x(x+2)1(x+2) x(x + 2) - 1(x + 2) .
  • Step 5: Factor out the common terms:
    (x+2)(x1)(x + 2)(x - 1).

Thus, the product representation of the function is (x+2)(x1) (x + 2)(x - 1) .

Answer

(x+2)(x1) (x+2)(x-1)

Exercise #20

Find the standard representation of the following function

f(x)=(x2)2+4 f(x)=(x-2)^2+4

Video Solution

Step-by-Step Solution

We need to convert the given function f(x)=(x2)2+4 f(x) = (x-2)^2 + 4 to standard form.

To expand (x2)2 (x-2)^2 , we use the formula (ab)2=a22ab+b2 (a-b)^2 = a^2 - 2ab + b^2 . Applying this to (x2)2 (x-2)^2 , we get:

  • (x2)2=x24x+4 (x-2)^2 = x^2 - 4x + 4 .

This accounts for the expanded square. Next, we add the constant term 4 4 from the original function (x2)2+4 (x-2)^2 + 4 :

  • f(x)=x24x+4+4 f(x) = x^2 - 4x + 4 + 4 .

Simplify by combining the constant terms:

  • f(x)=x24x+8 f(x) = x^2 - 4x + 8 .

The standard form of the function is thus f(x)=x24x+8 f(x) = x^2 - 4x + 8 .

Answer

f(x)=x24x+8 f(x)=x^2-4x+8