The function is and the point is .

The slope of tangent is the derivative of the curve at the given point.

The slope of the tangent line at is

The equation of the tangent at :

Point - Slope form: .

Substitute and in the above formula.

The equation of the tangent line is .

Let are slopes of two lines.

Two lines are perpendicular if and only if .

Normal line is perpendicular to the tangent line.

The product of their slopes is .

Here consider the slope of the tangent line as  and slope of the normal line as .

Therefore ,

Point - Slope form: .

Find the equation of the normal line at   with slope .

The equation of the tangent line is  .

The equation of the normal line  is .