Question

question
given $f(x) = 4x^2 + 2$, find $f(-9)$

Explanation:

Step1: Substitute \( x = -9 \) into the function

We have the function \( f(x) = 4x^2 + 2 \). To find \( f(-9) \), we replace \( x \) with \( -9 \) in the function. So we get \( f(-9)=4\times(-9)^2 + 2 \).

Step2: Calculate the square of \(-9\)

First, we calculate \( (-9)^2 \). Remember that the square of a negative number is positive, so \( (-9)^2=(-9)\times(-9) = 81 \). Then our expression becomes \( f(-9)=4\times81 + 2 \).

Step3: Multiply 4 and 81

Next, we calculate \( 4\times81 \). \( 4\times81 = 324 \). Now the expression is \( f(-9)=324 + 2 \).

Step4: Add 324 and 2

Finally, we add 324 and 2. \( 324+2 = 326 \).

Answer:

\( 326 \)