# Math Help - finding equation of a tangent line

1. ## finding equation of a tangent line

Find the equation of the tangent line to the following curve at the given point P. Illustrate by graphing the curve and the tangent line on the same screen.

what formula should i use for this

2. Basic differentiation

$\frac{d}{dx} x^n=nx^{n-1}$

And if $y= ax^n+bx^{n-1}+...$

Then $\frac{dy}{dx}=anx^{n-1}+(n-1)bx^{n-2}+...$

Then insert x value of P into the $\frac{dy}{dx}$ expression to get the gradient of the desired tangent line and then using the line equation y=mx+c and the coordinates of the point P will give you your answer.