Hello everyone. Much to my chagrin, I am having an algebraic problem. Here is the question:

Question:

Find the length of the curve analytically by anti-differentiation. You will need to simplify the integrand algebraically before finding an anti-derivative.

Solution:

I understand everything up to this point. In the answer, this is what it does after the prior step:

What happened to the 1? What happened to the negative sign? Any help is appreciated. Thanks in advance.