How do you solve this problem:
if f(x)=-x^2+2x-5, find f(-2)
Ok, what you do is you replace all the x's. You would get f(x)=(-2)^2+2(-2)-5. It is important, if entering it in a calculator, to put the parentheses () around the "x", because if you put -2^2, the calculator will think that means the negative of 2 squared. Then you solve and your answer should be what is left.
Is this synthetic division? or you have to factor this?
if synthetic division
x - 2 = 0
x = 2
2 | 1 2 -5
| 2 8
| 1 4 3
|
Line {1}
You multiply 2 x 1 = 2
2 x 4 = 8
x + 4 = 0
Remainder = 3
x - 1
_________________
x + 3 | x^2 + 2x - 5
- x^2 + 3x
-1x - 5
- -1x - 3
-2
Are you sure you copy the equation, right?
oh ok im sorry, i think the first person is right.
To find f(-2), we need to substitute -2 into the expression for f(x), which is -x^2+2x-5.
Step-by-step solution:
1. Replace every occurrence of x in the expression with -2:
f(-2) = -(-2)^2 + 2*(-2) - 5
2. Simplify the expression inside the parentheses first:
f(-2) = -(4) + (-4) - 5
3. Continue simplifying by performing the multiplication and addition/subtraction operations:
f(-2) = -4 - 4 - 5
= -8 - 5
= -13
Therefore, f(-2) = -13.