令y'=p
p'=1+p²
dp/dx=1+p²
1/(1+p²)dp=dx
两边积分,得
arctanp=x+c1
y'=tan(x+c1)
dy/dx=tan(x+c1)
dy=tan(x+c1)dx
两边积分,得
y=ln|sec(x+c1)|+c2
令y'=p
p'=1+p²
dp/dx=1+p²
1/(1+p²)dp=dx
两边积分,得
arctanp=x+c1
y'=tan(x+c1)
dy/dx=tan(x+c1)
dy=tan(x+c1)dx
两边积分,得
y=ln|sec(x+c1)|+c2