Vertex Representation: Transition between different representations of a function

Examples with solutions for Vertex 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)=(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 #3

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 #4

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 #5

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 #6

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 #7

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 #8

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

Exercise #9

Find the standard representation of the following function

f(x)=(x2)25 f(x)=(-x-2)^2-5

Video Solution

Step-by-Step Solution

To find the standard representation of the quadratic function f(x)=(x2)25 f(x)=(-x-2)^2-5 , we'll proceed with the following steps:

  • Step 1: Expand the quadratic expression (x2)2(-x-2)^2.
  • Step 2: Simplify the expression resulting from the expansion.
  • Step 3: Subtract the constant term 5-5.

Let's execute these steps in detail:

Step 1: Expand the expression (x2)2(-x-2)^2.
To expand, use the formula (a+b)2=a2+2ab+b2(a+b)^2 = a^2 + 2ab + b^2, where a=xa=-x and b=2b=-2.
(x2)2=(x)2+2(x)(2)+(2)2(-x-2)^2 = (-x)^2 + 2(-x)(-2) + (-2)^2.

Step 2: Calculate the expanded form.
(x)2=x2(-x)^2 = x^2,
2(x)(2)=4x2(-x)(-2) = 4x,
and (2)2=4(-2)^2 = 4.
Combining these, we have:
x2+4x+4x^2 + 4x + 4.

Step 3: Incorporate the constant from the original function.
The original function is f(x)=(x2)25f(x)=(-x-2)^2-5. Thus, we subtract 5 from the expanded result:
f(x)=x2+4x+45f(x) = x^2 + 4x + 4 - 5, which simplifies to:
f(x)=x2+4x1f(x) = x^2 + 4x - 1.

Therefore, the standard form of the given quadratic function is f(x)=x2+4x1 f(x) = x^2 + 4x -1 .

Answer

f(x)=x2+4x1 f(x)=x^2+4x-1

Exercise #10

Find the standard representation of the following function

f(x)=(x6)2+2x f(x)=(x-6)^2+2x

Video Solution

Step-by-Step Solution

To solve this problem, we'll transform the given expression into standard quadratic form by expanding and simplifying:

  • Step 1: Expand (x6)2 (x - 6)^2
    (x6)2=x212x+36 (x - 6)^2 = x^2 - 12x + 36
  • Step 2: Add 2x 2x
    f(x)=x212x+36+2x f(x) = x^2 - 12x + 36 + 2x
  • Step 3: Simplify
    Combine like terms: 12x+2x=10x-12x + 2x = -10x, resulting in the expression:
    f(x)=x210x+36 f(x) = x^2 - 10x + 36

Therefore, the standard form of the function f(x) f(x) is x210x+36 x^2 - 10x + 36 . This corresponds to choice 1 in the given list.

Thus, the final solution is f(x)=x210x+36 f(x) = x^2 - 10x + 36 .

Answer

f(x)=x210x+36 f(x)=x^2-10x+36