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Find (f circle g)(x) f(x) = x squared + 4 g(x) = 2x

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kristenmarieb... | Student, Grade 10 | Valedictorian

Posted February 22, 2013 at 12:11 AM via web

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Find (f circle g)(x)

f(x) = x squared + 4

g(x) = 2x

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embizze | High School Teacher | (Level 1) Educator Emeritus

Posted February 22, 2013 at 12:32 AM (Answer #1)

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We are asked to find the composition `(f@g)(x)` when `f(x)=x^2+4,g(x)=2x` :

`(f@g)(x)=f(g(x))` . Much like evaluating f(2), we substitute the expression for g(x) into f(x):

`(f@g)(x)=f(g(x))=(2x)^2+4=4x^2+4`

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`(f@g)(x)=4x^2+4`

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