- #1
spaghetti3451
- 1,344
- 33
I am trying to do the following integral:
$$\int_{\pi f}^{3\pi f} dx \sqrt{\cos(x/f)}.$$
Wolfram alpha - http://www.wolframalpha.com/input/?i=integrate+(cos(x))^(1/2)+dx+from+x=pi+to+3pi gives me
$$\int_{\pi f}^{3\pi f} dx \sqrt{\cos(x/f)} = 4f E(2) = 2.39628f + 2.39628if,$$
where E is the elliptic function.
Mathematica also gives me the same answer. How can the integral of a real integrand with real limits be complex?
$$\int_{\pi f}^{3\pi f} dx \sqrt{\cos(x/f)}.$$
Wolfram alpha - http://www.wolframalpha.com/input/?i=integrate+(cos(x))^(1/2)+dx+from+x=pi+to+3pi gives me
$$\int_{\pi f}^{3\pi f} dx \sqrt{\cos(x/f)} = 4f E(2) = 2.39628f + 2.39628if,$$
where E is the elliptic function.
Mathematica also gives me the same answer. How can the integral of a real integrand with real limits be complex?