Edexcel IGCSE Maths 4MA0 3H 21st May 2015

can someone explain functions like composite functions and inverse functions to me please they hard i dont understand atm pls hurry

so for inverse functions, e.g. find the inverse of f(x) = 3x/2, here's what you do:

set the f(x) bit to y, so the function looks like y = 3x/2

reverse y and x, so the function becomes x = 3y/2

rearrange for y, so then 2x = 3y, so y = 2x/3

therefore the inverse function is f-1(x) = 2x/3.

composite functions basically involves embedding one function into another function, e.g. if f(x) = 2x + 2 and g(x) = 3x/4 find f(g).

this question means you are putting the g function into the f function.what you have to do is replace all the x's in the f function with the g function.

so if f(x) = 2x + 2, then putting g into that makes 2(3x/4) + 2. expanding that out gives you f(g) = 3x/2 + 2. that's it!

hope that makes it clearer (:

how was it ???

wasnt good at all

It was quite good, just the last question was BRUTAL, for me at least.