The differential equation of the family of curves y=Ae3x+Be5x,where A and B are arbitrary constants, is
⇒dydx=3Ae3x+5Be5x
⇒d2ydx2=9Ae3x+25Be5x
By checking all the options, we have
∴d2ydx2−8dydx+15y
=9Ae3x+25Be5x−8(3Ae3x+5Be5x)+15(Ae3x+Be5x)
=9Ae3x+25Be5x−24Ae3x−40Be5x+15Ae3x+15Be5x
=9Ae3x−24Ae3x+15Ae3x+25Be5x−40Be5x+15Be5x
=0
∴d2ydx2−8dydx+15y=0