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 ▸

A bag contains 5 red beads and 7 blue beads. Two beads are removed at random without replacement. Workout the probability that the two beads are the same colour.


Use completing the square to find the minimum of y = x^2 - 4x + 8


Solve the equation x^2-9x+20


Show that (x + 1)(x + 2)(x + 3) can be written in the form ax3 + bx2 + cx + d where a, b, c and d are positive integers.