- #1

Callumnc1

- 877

- 103

- Homework Statement:
- Please see below

- Relevant Equations:
- Please see below

For this problem,

The solution is

However, I don't understand the statement circled in red. I don't understand why ## x = - \sqrt{x^2}##? They did not explained why.

I remember a year ago a calculus teacher showed me how to solve this type of problem. They divided the numerator by ##\sqrt{(-x)^2} = \sqrt{(x)^2}## and the denominator by ##-x##. I don't know why you have to divide by negative x for x approaches negative infinity, but this method works and give me the same result as the books method.

Many thanks!

The solution is

However, I don't understand the statement circled in red. I don't understand why ## x = - \sqrt{x^2}##? They did not explained why.

I remember a year ago a calculus teacher showed me how to solve this type of problem. They divided the numerator by ##\sqrt{(-x)^2} = \sqrt{(x)^2}## and the denominator by ##-x##. I don't know why you have to divide by negative x for x approaches negative infinity, but this method works and give me the same result as the books method.

Many thanks!