Question

微积分和积分问题∫ln3xdx=?d(?)=eˆ2xdxdtan2x=(?)dx求y=x(x-1)在x=2处切

Answer 1

xln3x-x (分部积分法）(1/2)e^2x2sec^2(2x)dy/dx=2x-1,在x=2处斜率为3,切线为y-2=3(x-2),即y=3x-4, 法线为y-2=-1/2(x-2),即x+2y-6=0sinx=x-(x^3)/6+(x^5)/5!+., 所以sin(π/3)≈π/3-(π/3)^3/6≈0.86