-f(x)=x^2+5

To find f(x), we need to change the sign of the function f(x):

f(x) = -x^2 - 5

To find the value of f(x), you need to substitute the given x value into the equation -f(x) = x^2 + 5. In this case, the equation is -f(x) = x^2 + 5.

First, let's start by rearranging the equation to solve for f(x). Since -f(x) is equal to x^2 + 5, we can rewrite it as f(x) = -(x^2 + 5).

Now, to find f(x), you can replace x in the equation f(x) = -(x^2 + 5) with the given value. For example, if x = 2, then you would replace x with 2 in the equation:

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

Simplifying the equation further:

f(2) = -(4 + 5)
f(2) = -(9)
f(2) = -9

So for x = 2, the value of f(x) is -9.

To find the value of f(x) when f(x) = x^2 + 5, you can substitute the given value into the equation.

So, f(x) = (x)^2 + 5

Therefore, if you substitute any value for x, you can find the value of f(x) by simply squaring the value of x and adding 5 to it.

For example, if x = 2, then:

f(2) = (2)^2 + 5
= 4 + 5
= 9

So, when x = 2, f(x) = 9.

Similarly, you can substitute any other value of x to find the corresponding value of f(x).