Results 1 to 6 of 6

Math Help - help to solve this differentail equation

  1. #1
    Newbie
    Joined
    Jun 2014
    From
    morocow
    Posts
    3

    help to solve this differentail equation

    Hi Guys



    i need help to solve this differentail equation :

    cos^2 x sinx d' =cos^3x.y+1


    i tried many times to solve this question but i could not

    so please help me to solve question
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,697
    Thanks
    1513

    Re: help to solve this differentail equation

    You probably haven't received any help yet because the way you have posted your DE is difficult to read.

    Is this your DE?

    $\displaystyle \begin{align*} \cos^2{(x)} \sin{(x)} \,\frac{\mathrm{d}y}{\mathrm{d}x} = y\cos^3{(x)} + 1 \end{align*}$
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jun 2014
    From
    morocow
    Posts
    3

    Re: help to solve this differentail equation

    Yes correct

    Please solve it
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,697
    Thanks
    1513

    Re: help to solve this differentail equation

    Rewrite it as

    $\displaystyle \begin{align*} \cos^2{(x)}\sin{(x)}\,\frac{\mathrm{d}y}{\mathrm{d }x} &= y\,\cos^3{(x)} + 1 \\ \frac{\mathrm{d}y}{\mathrm{d}x} &= \frac{y\,\cos^3{(x)} + 1}{\cos^2{(x)}\sin{(x)}} \\ \frac{\mathrm{d}y}{\mathrm{d}x} &= y\,\frac{\cos{(x)}}{\sin{(x)}} + \frac{1}{\cos^2{(x)}\sin{(x)}} \\ \frac{\mathrm{d}y}{\mathrm{d}x} - \frac{\cos{(x)}}{\sin{(x)}}\,y &= \frac{1}{\cos^2{(x)}\sin{(x)}} \end{align*}$

    This is now first order linear, so you can solve the DE using an integrating factor.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Jun 2014
    From
    morocow
    Posts
    3

    Re: help to solve this differentail equation

    Thanks bro.

    Is this complete answer ??
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,697
    Thanks
    1513

    Re: help to solve this differentail equation

    No, now you actually have to solve the DE... Have you tried anything at all?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: March 17th 2013, 08:47 PM
  2. need to solve summation equation to solve sum(x2)
    Posted in the Statistics Forum
    Replies: 2
    Last Post: July 16th 2010, 10:29 PM
  3. Differentail geometry
    Posted in the Geometry Forum
    Replies: 2
    Last Post: February 9th 2010, 10:53 AM
  4. Differentail Equation
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: January 14th 2010, 03:49 AM
  5. differentail equation solution
    Posted in the Calculus Forum
    Replies: 4
    Last Post: April 30th 2009, 10:55 PM

Search Tags


/mathhelpforum @mathhelpforum