Ques. 1JEE Main 2024, 27 January (Morning Shift)
If the solution of the differential equation (2x+3y-2) dx+(4x+6y-7) dy=0, y(0)=3, is x+ y+3 e|2x+3y- |=6, then +2 +3 is equal to .
Answer
29
Solution
Put 2x+3y=t ⇒ 2+3 dydx= dtdx, and dydx=- t-22t-7
⇒ dtdx=2- 3(t-2)2t-7= t-82t-7
⇒ (2+ 9t-8 )dt= dx ∵ 2t-7t-8=2+ 9t-8
⇒ 2t+9 |t-8|=x+C
x=0, y=3: t=9 ⇒ C=18
⇒ 4x+6y+9 |2x+3y-8|=x+18
⇒ x+2y+3 |2x+3y-8|=6 (÷3)
∴ =1, =2, =8 ⇒ +2 +3 =1+4+24=29
Answer: 29