Question

If f(x) = x^2 + 4 and g(x) = V1 - x, what is the value off(g(-3)) ?

Answer 1

First, substitute -3 into g ( x ) for x

`Hence,g(-3)=\text{ }\sqrt{1\text{ - ( -3 ) }}\text{ = }\sqrt{1\text{ + 3 }}\text{ = }\sqrt{4\text{ }}\text{ = 2 }`

So g ( - 3 ) = 2 , Next, sujbstitute 2 for x in f (x)

`f(g(-3))=f(2)=(2)^2\text{ + 4 = 4 + 4 = 8 }`

Therefore the value of f (g ( -3 ) ) is 8