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Question
Answer the following:
Find f ° g and g ° f : f(x) = x2 + 5, g(x) = x – 8
Solution
f(x) = x2 + 5, g(x) = x – 8
(f ° g) (x) = f[g(x)]
= f(x – 8)
= (x – 8)2 + 5
= x2 – 16x + 64 + 5
= x2 – 16x + 69
(g ° f) (x) = g[f(x)]
=g[x2 + 5)
= (x2 +5) – 8
= x2 – 3
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