Convert the Quadratic Expression (-x-2)² - 5 to Its Standard Form

Question

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