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Ignore c. I only need help with a and b

Ignore c. I only need help with a and b-example-1
User Ratna Dinakar
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1 Answer

10 votes
10 votes

Part A.

The composition of f ang g is given by


(f\circ g)(x))=f(g(x))=((3x+7)-7)/(3)

where we have inserted 3x-7 in the place of x in function f. Then, we have


(f\circ g)(x))=f(g(x))=(3x+7-7)/(3)=(3x)/(3)=x

Therefore, the answer is


(f\circ g)(x))=x

Part B

Similarly to the previous case, we have


(g\circ f)(x))=g(f(x))=3((x+7)/(3))-7

which gives


(g\circ f)(x))=g(f(x))=x+7-7=x

then, the answer is


(g\circ f)(x))=x

Part C.

In the first case, x belongs to the domain of g and g(x) belongs to the domain of f. Then, the domain of the composition (fog)(x) is all real numbers.

Similarly, in the second case, x belongs to the domain of f and f(x) belongs to the domain of g. Then, the domain of the composition (gof)(x) is all real numbers. Then, the domains are the same (all real numbers).

User Moumen Alisawe
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