Q.

Let y=y(x) be the solution of the differential equation  dydx=4y3+2yx23xy2+x3,y(1)=1. If for some nN,y(2)[n1,n), then 2n is equal to ____________ 

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

answer is 6.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail

Given differential equations is

dydx=yx(4y2+2x2)(3y2+x2)

Put y=vxdydx=v+xdvdx

v+xdvdx=v(4v2+2)(3v2+1)

v+xdvdx=v(4v2+2)(3v2+1)

xdvdx=v((4v2+23v21)3v2+1)

xdvdx=v3+v3v2+13v2+1v3+vdv=dxx

Take integral both sides,

(3v2+1)dvv3+v=dxx

ln|v3+v|=lnx+c

ln|(yx)3+(yx)|=lnx+C

Here,y(1)=1 and  C=ln2

Here y(2)[n1,n)

ln(y38+y2)=2ln2y38+y2=4

[y(2)]=2

Therefore,
 n=3 2n=6

Watch 3-min video & get full concept clarity

hear from our champions

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon
Let y=y(x) be the solution of the differential equation  dydx=4y3+2yx23xy2+x3,y(1)=1. If for some n∈N,y(2)∈[n−1,n), then 2n is equal to ____________