What is the equation of the normal line of #f(x)=x^3e^-x+x^3# at #x=-5#?
The normal equation is
the slope of the normal line is the negative reciprocal of the slope of the tangent line. so what you need to don is :
1) find the the slope of f(x) at
2) find the equation of line, equation of tangent at (-5, f(5))
a) Tangent equation,
4) The normal equation is
There is some algebra that you need to, which I leave to you. the recipe for solving is there for you for now and future problems...