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Let f(x) = x² + 3x - 2 and g(x) = √√x + 1. Find and simplify: (g°f)(x)

User Jianru Shi
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1 Answer

16 votes
16 votes

Answer:

(g ° f)(x)​ = √ x^2 + 3x - 1

Step-by-step explanation:

The expression (g ° f)(x)​ is the same as g(f(x)).

Therefore, to evaluate (g ° f)(x)​, we replace x in g(x) with f(x).

Now,


g(x)=√(x+1).
\therefore g(f(x))=√(f(x)+1)

Since f(x) = x² + 3x - 2, the above gives


g(f(x))=√(x^2+3x-2+1)

which simplifies to give


g(f(x))=√(x^2+3x-1)

Hence,


\boxed{(g\circ f)(x)=x^2+3x-1.}

which is our answer!

User Nicholas Robinson
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