Question

Given : f(x) = x2 - 5 and g(x) = 3x - 1 Find 2g (f(-5))

Answer 1

The given functions are

f(x) = x^2 - 5

g(x) = 3x - 1

To find 2g(f(- 5)), we would first find f(- 5)

To find f(- 5), we would substitute x = - 5 into f(x) = x2 - 5. It becomes

f(- 5) = (- 5)^2 - 5

f(- 5) = 25 - 5

f(- 5) = 20

Then, we would substitute f(- 5) = 20 into g(x) = 3x - 1

Thus,

g(f(- 5) = 3*20 - 1

g(f(- 5) = 60 - 1

g(f(- 5) = 59

Therefore,

2g(f(- 5)) = 2 * 59 = 118