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

Related Maths GCSE answers

All answers ▸

Factorise 3x+12


How do we factorise an expression?


two connected triangles in an overall shape ABCD, find length AD


What is the quadratic formula and how do I use it?