Find all x-coordinates of points (x,y) on the curve of where the tangent line is horizontal. (Thanks!!)
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Originally Posted by Affinity Find all x-coordinates of points (x,y) on the curve of where the tangent line is horizontal. (Thanks!!) The tangent line will be horizontal when y'(x) = 0. So: Using the quotient rule: Doing a little factoring: We need to solve this for y'(x) = 0. As long as may simply set the numerator equal to 0: This will obviously happen at x = 2 and x = 7. -Dan