F(x)= √x-5. find f-2

Question

asked Oct 21, 2019 146k views

1 Answer

Akash Kubavat · Answer 1 · 2019-10-25T02:07:45+0000

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:

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