The function is  and point .

Slope of the tangent line is the derivative of the function at .

Consider .

Apply derivative on each side with respect to .

.

Power rule of derivatives : .

Constant rule of derivatives :.

.

Substitute in .

Slope of the tangent line is .

Point slope form of line equation : .

Substitute and in the avove equation.

The tangent line equation is .

Graph:

Graph the function and tangent line .

The differential equation is .

The tangent line equation is .