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Consider the equation.\(\frac{dy}{dx}\) + y = sin xWhat is the order and degree of this equation?Find the integrating factor. Solve this equation. |
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Answer» 1. Order = 1, Degree = 1 2. Given, \(\frac{dy}{dx}\) + y = sin x is of the form \(\frac{dy}{dx}\)+ Py = Q ⇒ P = 1, Q = sinx Integrating factor = e∫Pdx = e∫1dx = ex 3. Therefore solution is y.IF = ∫Q.IFdx + c ⇒ yex = ∫ex sinxdx + c ____(1) ∫sinx.exdx = ex sinx – ∫cosx.exdx = ex sin x – cosx.ex – ∫sinx.ex dx ⇒ 2∫ex sin xdx = ex(sin x – cos x) ⇒ ∫ex sinxdx =\(\frac{e^x}{2}\)(sinx – cosx) (1) ⇒ yex = \(\frac{e^x}{2}\)(sinx – cosx) + c. |
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