Question

If f(x) = 3x +7 and g(x) = x2 - 2x, what is g(f(1)) equal to? Answer: If f(x) = x + 4 and g(x) = 2x + 1, find (g o f)(x). Select one: a. 2x + 9 b. 2x^2 + 9x + 4 c. 2x^2 + 4 d. 2x + 5

Answer 1

80 and 2x + 9

Explanation:

to evaluate g(f(1)) , evaluate f(1) then substitute the value obtained into g(x)

f(1) = 3(1) + 7 = 3 + 7 = 10 , then

g(10) = 10² - 2(10) = 100 - 20 = 80

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to calculate (g ￮ f)(x) , substitute x = f(x) into g(x)

(g ￮ f)(x)

= g(f(x))

= g(x + 4)

= 2(x + 4) + 1

= 2x + 8 + 1

= 2x + 9