Plutonium88
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Homework Statement
The tangent to the function y=3x(x-3) at point P(2,-6) is the hypotenuse of a right triangle that forms with the coordinate axes. Find Area
The Attempt at a Solution
First of all, i know that i A=BxH/2 so i need the opposite and adjacent sides of this triangle.
Okay so personally i graphed the function at first, and then drew the tangent at the point 2,-6. I then connected the line to the x and y axes. I did this because it says it forms a triangle with the coordinate axes.I read that the coordinate axis are respectively the x and y axis, so i thought that this made sense. Can some one reassure me about this?
Next i thought that i would need the slope of the tangent at that point because it would relate to the slope of hypotenuse of the triangle.
So i took the limit.
Lim (f(x+h)-f(x))/H
H->0
where P(2,-6), so x=2
solving this limit i got
Lim 6x+h-9 = 6x-9
H->0
and when x=2
the limit is = 3
therefore the slope of the tangent is 3. mt=3
so I'm curious, does this mean that the hypotenuse also = 3 because it says the the tangent at the point is the hypotenuse. Or would the hypotenuse side be the tangent line (6x-9)?
So yea this is my dilemma..