Question

1

Given f(x) = V7x
V7x and g(x) =
х
Which value is in the domain of fºg?
8

Answer 1

f(x) = √7x

g(x) = 1/x -8

To find the domain of f º g we must first find f o g(x)

To find f o g(x) wherever you see x in f(x) replace it by g(x)

That's

f o g = √7(1/x-8)

= √7 / √x - 8

To find the domain equate the denominator to zero

That's

√x - 8 = 0

Square both sides

(√x - 8)² = 0²

x - 8 = 0

x = 8

The domain of f o g is x E R except 8

Hope this helps