Question

If s(x) = 2 – x2 and t(x) = 3x, which value is equivalent to (s circle t) (negative 7)?

–439

–141

153

443

Answer 1

-439

Explanation:

a on edge

Answer 2

-439

Explanation:

(s circle t) (negative 7) is a notation for a compound function.

A compound function is a function that has as an argument another function.

Another notation for this compound function is s(t(-7)), that is, the result of the function t(-7) is the value that will be used in the function s(x).

So, first we calculate the value of t(-7):

t(x) = 3x

t(-7) = 3*(-7) = -21

Now, we apply this value for s(x):

s(x) = 2 - x2

s(t(-7)) = s(-21) = 2 - (-21)^2 = 2 - 441 = -439