help plzzzz
i dunno
any ideas?
not sure if this will work out, v = 4x+y+1 dv/dx = 4 + dy/dx => dy/dx = dv/dx - 4 => dv/dx - 4 = v^2 .. .. Not sure if this will work. wolfram is giving different answer!! http://www.wolframalpha.com/input/?i=y%27+%3D+%284x%2By%2B1%29%5E2
\[ \frac{dv}{4 + v^2} = dx\] Integrating both sides, \[ \tan^-1(\frac v 2) = x +c\implies 4x+y+1 = \tan(x+c)\] Not sure if this will work ..!!
Let 4x+y+1=v Then y=v-4x-1 and dy/dx=dv/dx-4 the DE becomes \[\large{\frac{dy}{dx}=v^2+4}\] which is a separable \[\large{\frac{dv}{v^2+4} =dx}\] Integrate both sides \[\frac{1}{2}\tan^{-1}(\frac{v}{2})=x+C\] \[v= 2\tan (2x+C)\] therefore \[y=2\tan (2x+C) - 4x -1\]
looks like i missed 1/a part
yep i din see the problem in the correct way @experimentX and @lalaly thanks you for your help.
yw
:)
Join our real-time social learning platform and learn together with your friends!