What is the equation of the line normal to # f(x)=xtanx# at # x=pi/3#?
Let us find the slope of the tangent, which should give us slope of normal (as it is perpendicular to tangent and hence product of their slopes would be
Slope of tangent is given by first derivative and this is
and slope of normal is
As normal is needed at
Hence, using point slope form of equation
Equation of normal is