wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Find points at which the tangent to the curve y=x33x29x+7 is parallel to the x-axis.

Open in App
Solution

The equation of the given curve is y=x33x29x+7 .

dydx=3x26x9
Now, the tangent is parallel to the x-axis if the slope of the tangent is zero.
3x26x9x22x3=0
(x3)(x+1)=0
x=3orx=1
When x=3,y=(3)33(3)29(3)+7=272727+7=20.
When x=1,y=(1)33(1)29(1)+7=139+7=4.
Hence, the points at which the tangent is parallel to the x-axis are (3,20) and (1,4).

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Geometrical Interpretation of a Derivative
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon