Find the Standard Representation of (2x+1)² - 1

Question

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