Recent content by zhiyuanhou

ha ha! Weierstrass substitution is well! Thank you!

Hi everyone, when I was dealing with a physics problem, I find a definite integral and I cannot solve it. \int_{0}^{2\pi}\frac{1}{(a+cosx)^{2}}dx a is constant. Thank you!

OK , I think I have got your mean. In my opinion, the following is wrong. 1)When you exert a force on the disc, you forget the force exerted by the rotational axis. 2)F=ma is right for the particle, and your disc aren't treated as particle. So if you want use F=ma, you must treat the disc...

I am sorry. Could you tell me what is the 'T' and what is the 'I'?