y‘=-x的负二次方所以切线的斜率为负4切线方程为y-2=-4X(x-1/2)得y+4x-4=0法线的斜率为1/4法线方程为y-2=1/4X(x-1/2)得8y-2x-15=0
先对x求导得 y'=-(1/x)的2次方令x=1/2 则 y’=-4则可求得切线方程 y-2=-4(x-1/2)法线方程为y-2=1/4*(x-1/2)
