Help - Inequality Problem with an Exponential

[yosef.javed]

I need help trying to understand what I'm doing wrong in solving this problem.

Find all possible solutions for x.
1-x^2>=0

Here is what I do:

1. 1-x^2>=0
Subtract 1 on both sides

2. -x^2>=-1
Divide by -1 on each side. Inequality flips.

3. x^2<=1
Square root of x gives +-1

4. x<=+-1 or x<=1
My Answer!

Turns out to be wrong. What am I missing here?
Correct Answer: -1<=x<=1

[tim]

step 3: you can't just take the square root of both sides without further analysis. if you take the square root, the negative value would flip the sign so you should get x <= 1 and x >= -1, which corresponds to the correct answer..