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20 votes
Let f(x)=(x^2)+2
Let g(x)=1-3x
(fg)(-1)
Find the Value of each Function.

1 Answer

3 votes
f(x)=x² +2 —(1)
f[g(x)]=(g(x))² +2 —(2)
substitute the function g(x) into (2)
f[g(x)]= (1-3x)² +2
now x=-1
fg(-1)=(1-3(-1))² +2
=(1+3)² +2
= 16+2
= 18