The first one works out a little too easily. I'm suspecting a typo? Either way, it does work. Note that the first and last term are identical, except for a sign. So they add to zero. That leaves the second term, in which you can cancel a common 2 sqrtx, leaving 1/(cos x)^2. Since sec x = 1/cos x, we get (sec x)^2.Originally Posted byPhilipJ

Not sure what to make of your second problem.

If you typed it correctly, the problem is wrong. x/(x^1) = 1.x/(x^1) - x/(x^2+1)^2

-Dan