JEE Main20202 Sep 2020Evening ShiftMathematicsApplication of DerivativesActual
The equation of the normal to the curve y = 1 + x 2 y + cos 2 sin - 1 x , at x = 0 is
Options
- A  y + 4 x = 2
- By = 4 x + 2
- Cx   +   4 y   =   8
- D2 y   +   x   =   4
Correct answer
C. x   +   4 y   =   8
Step-by-step solution
y = 1 + x 2 y + cos 2 sin - 1 x Now at x = 0 ,   y = 2 Let sin - 1 x = t   ⇒ sin t = x ⇒ cos 2 sin - 1 x = cos 2 t = 1 - sin 2 t = 1 - x 2 y = 1 + x 2 y + 1 - x 2 y = e 2 y ln 1 + x + 1 - x 2 d y d x = e 2 y ln ( 1 + x ) 2 y 1 + x + ln ( 1 + x ) · 2 d y d x - 2 x Now at x = 0 , d y d x = 2 × 2 1 + 0 + 0 d y d x = 4 y - 2 = - 1 4 x - 0 4 y - 8 = - x x + 4 y = 8