hey i need some help with tangent lines, i just dont understand it at all. I need to figure out how to find the equation of the tangent line to f(x)=x^3 at the point where x=3...much thanks

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- Sep 24th 2007, 10:07 PMmer1988tangent lines
hey i need some help with tangent lines, i just dont understand it at all. I need to figure out how to find the equation of the tangent line to f(x)=x^3 at the point where x=3...much thanks

- Sep 24th 2007, 10:11 PMJhevon
remember, a line is of the form where is the slope, and is the y-intercept.

how do we find the slope? well, from the derivative of course. find and plug in to get the slope at that point, then use the point slope form.

where is the point on the graph when

just solve for y to get the equation of the line