y'=sec²(x+y)* (1+y')怎么变到y'=sec²(x+y)/[1-sec²(x+y)]

y'=sec²(x+y)* (1+y')怎么变到y'=sec²(x+y)/[1-sec²(x+y)]
y'=sec²(x+y)* (1+y')怎么变到y'=sec²(x+y)/[1-sec²(x+y)]

y'=sec²(x+y)* (1+y')怎么变到y'=sec²(x+y)/[1-sec²(x+y)]
将右边的括号拆开,带有y'的项移到左边,提出y',将y'前面的系数项除到右边就行了.