MHT CET202121 Sep 2021Morning ShiftMathematicsApplication of DerivativesActual
The curves x^2 a^2 + y^2 4 =4 and y^3=16 x intersect each other orthogonally, then a ^2=
Options
- A2
- B3 4
- C1 2
- D4 3
Correct answer
D. 4 3
Step-by-step solution
aligned & x^2 a^2 + y^2 4 =1 & 1 a^2 2 x+ 1 4 2 y d y d x =0 d y d x = ( -x a^2 ) ( 4 y ) aligned Also y ^3=16 x 3 y^2 d y d x =16 d y d x = 16 3 y^2 Since curves intersect orthogonally, from (1) and (2), we write ( -x a^2 ) ( 4 y ) ( 16 3 y^2 )=-1 64 x 3 a^2 y^3 =1 and we have y^3=16 x 64 x 3 a ^2(16 x ) =1 a ^2= 4 3