Write the expressions for (g+f)(x) and (g-f)(x) and evaluate (g*f)(2).

Question

Suppose that the functions s
and t are defined for all real numbers
x as follows.

 

f(x)= 3x^2

 

g(x)= x-5

Answer 1

f(x) = 3x² and g(x) = x - 5

(g+f)(x) = 3x² + x - 5

(g-f)(x) = x - 5 - 3x² = -3x² + x - 5

(gof)(x) = 3x² - 5

(gof)(2) = 3(2)² - 5 = 12 - 5 = 7