Originally Posted by

**Kuma** I haven't done any sort of trig integrals in the past and i have pretty much forgotten all my identities since i haven't looked at them for over 3 years so please bear with me.

The question is:

upper limit = 1, lower limit = 0.

Integrate cos (x^2) with those bounds.

First off I had to approximate the integral using the midpoint/trapezoidal rules. Those were fairly straightforward. Now i want to check my answer but I'm kinda lost.

If i took the integral of cos (x^2), i would get sin(x^2) no? Mr F says: No. Differentiate it and you will see why.

Subbing in the limits of integration i would get sin(1) - sin(0) = sin (1)

but using the approximation rules above I got the integral as being approximately equal to one, which does not equal to sin (1).

Help?