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What is a ...
3 years ago
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Merle Corkery
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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
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Click here to view my profile and arrange a free introduction.A composite function is created when one function is substituted in another function.
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