Question

F(x)= √x-5. find f-2

Answer 1

For this case we have:

Be a function of the form
`y = f (x)`

Where:

`f (x) = \sqrt {x-5}`

If we want to find f (-2), we substitute
`x = -2`, then:

`f (-2) = \sqrt {-2-5}\\f (-2) = \sqrt {-7}`

Since we have a negative root, the result will be given by complex numbers. By definition:

`\sqrt {-1} = i`

So:

`f (-2) = \sqrt {7} i`

Answer:

`f (-2) = \sqrt {7} i`