Given $f(x) = 2x - 5$ and $g(x) = 2x^2 + 7$ how do you find f(g(x))?

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Answer 1 · 2016-01-25T17:43:13

$f(g(x)) = 4x^2 + 9$

$f(x) = 2x - 5$

$g(x) = 2x^2 + 7$

To find $f(g(x))$ , what you need to do is plug $g(x)$ for each occurence of $x$ in $f(x)$ :

$f(color(blue)(x)) = 2color(blue)(x) - 5$

$f(g(x)) = f(color(blue)(2x^2+7)) = 2 (color(blue)(2x^2+7)) - 5$

$= 4x^2 + 14 - 5 = 4x^2 + 9$

Given f(x) = 2x - 5f(x) = 2x - 5 and g(x) = 2x^2 + 7g(x) = 2x^2 + 7 how do you find f(g(x))?