Question

Given f(x)=x^2+5 and g(x)=2x^3-1 find (f/g)(-3)

Answer 1

For this case we have the following functions:

$f (x) = x ^ 2 + 5\\g (x) = 2x ^ 3-1$

By definition of composition of functions we have:

$(f / g) (x) = \frac {f (x)} {g (x)}$

Then substituting:

$f (-3) = (- 3) ^ 2 + 5 = 9 + 5 = 14\\g (-3) = 2 (-3) ^ 3-1 = 2 (-27) -1 = -54-1 = -55$

So:

$(f / g) (- 3) = \frac {14} {- 55} = - 0.25$

Answer:

$(f / g) (- 3) = \frac {14} {- 55} = - 0.25$