AP Calc help plz!!!!?
The curve y = x^3 + x^2 - x has two horizontal tangents. Find the difference in height of these two horizontal lines.
- daSVgrouchLv 77 years agoFavorite Answer
y'(x) = 3x^2 + 2x - 1 = 0 at the tangents
solve for the two values of x, (x = -1 and x = 1/3)
plug them into y(x) and then subtract the differences
- 7 years ago
A horizontal tangent is defined as a point where the derivative is zero.
y'=0 at x=-1/3 and 1
When you plug in those numbers to the original curve you get (-1/3,11/27) and (1,1)
Then you subtract their y values.
Therefore, 16/27 should be the difference in height.
- Anonymous7 years ago
the difference in height of these two horizontal lines = f(-1)-f(1/3)