MHT CET2012MathematicsApplication of Derivatives
All the points on the curve y²=4 a|x+a (x / a)| , where the tangent is parallel to the axis of x are lies on
Options
- Acircle
- Bparabola
- Cstraight line
- DNone of these
Correct answer
B. parabola
Step-by-step solution
y²=4 a [x+a ( x a ) ] ...(i) 2 y d y d x =4 a [1+ ( x a ) ] ...(ii) If tangent is parallel to x -axis, then d y d x =0 So, from Eq. (i), we get ( x a )=-1 ( x a )=0 On putting this value in Eq. (i), we get y²=4 a(x+0) y²=4 a x So, all the points on the curve y²=4 a (x+a x a ) where the tangent is parallel to the x -axis are lies on parabola.