Thread: A calc question
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Old 05-19-2004, 05:42 AM   #1 (permalink)
Stompy
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A calc question

Well, I guess it's more like an algebra problem since I understand the calc just fine.

I need to find an equation of the tangent line to the curve at the given point:

y = 1 + 2x - x^3 @ P(1 , 2)

To do this, I first need to find the slope with the following method: (f(x) - f(a)) / (x - a)

( (1 + 2x - x^3) - (2) ) / (x - 1)

becomes..

(2x - x^3 - 1) / (x - 1)

Top and bottom equal 0 if you plug in 1, so that means there's a way to factor them even further, correct? Meaning... (x + 1) * (?) = 2x - x^3 - 1 ?

The book says the answer is y = -x + 3, but I can't even get past simplifying (2x - x^3 - 1) / (x - 1) to get the slope.

Does x - 1 factor out of the numerator, or am I going about this all wrong?

Thanks for the help
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