What is the equation of the normal line of #f(x)=-7x^3-x^2-x-1# at #x=-8#?
1 Answer
Dec 14, 2015
Explanation:
Hence the slope of the tangent at
But the normal is perpendicular to the tangent and hence the slope of the normal at that point is
But the normal line is a straight line so of form
Substituting the point
Thus the normal has equation