1 calculus Q.

The 6th dy/dx is wrong. The denominator is (1 + x)^2, not (1 + x). So the numerator of the 2nd term should be (1 + x)^(3/2), not (1 + x)^(1/2).

2011-08-15 07:14:43 補充：
Remark : If I were you, I will not use this clumsy method. I will change it to y^2 = x^2[(1 - x)/(1 + x)] = (x^2 - x^3)/(1 + x) = f, so dy/dx = (df/dx)/2y.

2011-08-19 07:24:19 補充：
Since the common denominator is (1 + x)^2(1 - x)^(1/2) and the denominator of the 2nd term is (1 + x)^(1/2), so you have to multiply the 2nd term by (1 + x)^(3/2)(1 - x)^(1/2), but you multiply it by (1 + x)^(1/2)(1 - x)^(1/2), that is the mistake.