If you are given the function f(x) = 10-3x and g(x) = (x-3)/2 , find the value of the composite function gf(4) ?

The composite function can be thought of as if the function f(x) is the variable for the function g(x) instead of x. So first you find the value of the function f(4),f(4) = 10 - (3x4) = 10 - 12 = -2Now that we have found the value of f(4) we have found what we need to substitute as the variable into g(x) instead of x.gf(4) = (-2-3)/2 = -5/2 = -2.5

HL
Answered by Hajerah L. Maths tutor

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