How do you give the equation of the normal line to the graph of #y=2xsqrt(x^2+8)+2# at point (0,2)?
The answer is:
The normal line to the graph in one point is the perpendicular at the tangent line to the graph in that point.
Remembering that two lines
the slope of the tangent line in a point to a curve is the first derivative in that point,
The line that passes from a given a point