How do you integrate #sqrt(1+(4cos^2))dx#?

1 Answer
Aug 31, 2015

Normally, you might expect that the #1# be a #4# so you can just do trig substitution. Unfortunately we can't do that.

If you are not in a very advanced Calculus course, where you might work with elliptic integrals, you don't have to know how to do this analytically. At best you can do a numeric integral.

So, you can evaluate #int_a^b sqrt(1+4cos^2x)dx# on your calculator or on Wolfram Alpha, but it's not something I believe you have been taught to do by hand.

http://www.wolframalpha.com/input/?i=integral+of+sqrt%281%2B4cos^2%28x%29%29