Given the functions f(x) = (x + 2)/9 and g(x) = x^3 + 6, find fg(x).

Firstly, fg(x) could be written as f[g(x)], or in other words, the function f acts on the result of x going through the function g (Bear in mind that I'm using the square brackets only because it's easier to see). Hence, we could write fg(x) as f(x3 + 6). This is the same as writing [(x3 + 6) + 2]/9 because you're applying the function f to (x3 + 6) instead of just x. So this would give a final answer of fg(x) = [(x3 + 6) + 2]/9.

JJ

Related Maths GCSE answers

All answers ▸

If x:y = 7:4 and x+y = 88 , work out the value of x–y.


How can algebraic expressions be simplified?


In a competition, a prize is won every 2014 seconds. Work out an estimate for the number of prizes won in 24 hours. You must show your working. (4 marks)


Solve 5x – 3 > 3x + 11