Question

Evaluate ƒ(x) when x = 6. A. 6 (NOT the answer) B. 12 C. 74 D. 218

Answer 1

Answer:

The value of f(x) at x=6 is  $f(6) = 218$

Therefore, the correct option is D) 218

Step-by-step explanation:

We need to solve the value of f(x) at x=6

Given step function is $f(x)=6x^{2}+2$ for the range of  -6 < x < 9

( 6 is in this range)

Substitute the value x=6 in $f(x)=6x^{2}+2$ :

$f(x) = 6x^{2} + 2$

$f(6) = 6(6)^{2} + 2$

$f(6) = 6\times 36+ 2$

$f(6) = 216+ 2$

$f(6) = 218$

Hence, the value of f(x) at x=6 is  $f(6) = 218$

Therefore, the correct option is D) 218

Answer 2

After trying to do it the hard way, i remembered the easy way.

substitution:

because x = 6 and 6 is in the range of -6 < x < 9, we only need the equation 6x^(2) + 2

f(x) = 6x^(2) + 2
f(6) = 6(6)^(2) + 2
f(6) = 6(36) + 2
f(6) = 216 + 2
f(6) = 218