- #1
PWiz
- 695
- 116
Homework Statement
I was trying to find a general expression for the arc length of sine, i.e. ##\int \sqrt{1+cos^2 x} dx##, but got stuck. I made this problem up, and with some google searches realized that it uses something known as an elliptical integral. How do I go about using it here?
2. Homework Equations
Trig substitutions
The Attempt at a Solution
By letting ##cosx=tanu## and by differentiating arccos, I came down to the integral ##\int \frac{-sec^3 u}{\sqrt{2-sec^2 u}}du##, which seems as unsolvable as the original question.
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