Maths
>
A-Level
>
Algebra & Functions
>
What is a ...
3 years ago
ยท
2 Replies
ยท
1618 views
Merle Corkery
Use our concise notes and diagrams to only revise what you need to know.
By submitting your email, you agree to join our mailing list. You can unsubscribe at any time.
2 Answers
Help students achieve their goals by realising their potential.
2 reviews
A composite function is one where the input to the function is another function.
When one writes f(x), f is the output and x is a place-holder for some input; we say that the function f, is evaluated at x.
The placeholder x could be replaced with:
1) a number, 2 say: f(2)
2) another letter, q say: f(q)
3) a function or expression, g(x) = 3x - 2
f(3x - 2) or equivalently f(g(x)), sometimes written as fg(x)
---- Please note, fg(x) is NOT f multiplied by g(x). ----
So, if f(x) = 2x + 7, then
f(2) = 2(2) + 7 = 4 + 7 = 11
f(q) = 2q + 7
fg(x) = f(3x - 2) = 2(3x - 2) + 7
= 6x - 4 + 7
= 6x + 3
Found this useful? Give kudos!
I'm available for 1:1 private online tuition!
Click here to view my profile and arrange a free introduction.A composite function is created when one function is substituted in another function.
Found this useful? Give kudos!
Think you can help?
Get started with a free online introductions with an experienced and qualified online tutor on Sherpa.
Find an A-Level Maths Tutor