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The composition of functions

The composition of functions-example-1
User Jutta
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1 Answer

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Answer: g(f(5)) = 352

Explanation:

The question being asked is the same as finding g(f(5)).

What this means is to find f(5), and then plug that value into g(x) as x and solve.

f(5) = 4(5) + 1 = 20 + 1 = 21

g(f(5)) = g(21) = 21^2 - 4(21) - 5 = 441 - 84 - 5 = 357 - 5 = 352

Note: You could also find g(f(x)), and then plug 5 in as x and solve.

Start by plugging f(x) into g(x) such that you get g(x = f(x))

g(f(x)) = (4x + 1)^2 - 4(4x + 1) - 5

Now, replace x with 5 and solve to get g(f(5)).

g(f(5)) = (4(5) + 1)^2 - 4(4(5) + 1) - 5 = 352

User Greycon
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