Question: how to find the slope of the normal line?
Answer: By definition, the slope of the normal line is the opposite reciprocal of the slope of the tangent line. The slope of the tangent line is the derivative of the curve (function) at that point. For example, find the equation of the normal line for the function f(x) = -3x^2 + 2x + 6 at the point x = 1.