(a)

The function is and the point is .

Apply derivative on each side with respect to .

Sum rule of derivatives :

Constant multiple rule and the power rule :.

.

Find the slope of the tangent line at .

Substitute  in .

Slope of the tangent line is .

Point-slope form of line equation is .

Substitute and in the point-slope form.

The tangent line equation is .

(b)

The graph of the function and tangent line .

 (c)

Graph the function using derivative feature of a graphing utility.

The tangent line equation is .