Differential Equations

The general solution of the differential equation \[{{e}^{x}}~dy\text{ }+\text{ }\left( y\text{ }{{e}^{x}}~+\text{ }2x \right)\text{ }dx\text{ }=\text{ }0\text{ }isA.\text{ }x\text{ }ey\text{ }+\text{ }{{x}^{2}}~=\text{ }C\text{ }B.\text{ }x\text{ }ey\text{ }+\text{ }{{y}^{2}}~=\text{ }C\text{ }C.\text{ }y\text{ }ex\text{ }+\text{ }{{x}^{2}}~=\text{ }C\text{ }D.\text{ }y\text{ }ey\text{ }+\text{ }{{x}^{2}}~=\text{ }C\]

Therefore, the correct option is option(c).

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Prove that \[{{\mathbf{x}}^{\mathbf{2}}}~-\text{ }{{\mathbf{y}}^{\mathbf{2}}}~=\text{ }\mathbf{c}\text{ }{{\left( {{\mathbf{x}}^{\mathbf{2}}}~+\text{ }{{\mathbf{y}}^{\mathbf{2}}} \right)}^{\mathbf{2}}}~\] is the general solution of differential equation \[({{\mathbf{x}}^{\mathbf{3}}}-\mathbf{3x}{{\mathbf{y}}^{\mathbf{2}}})\text{ }\mathbf{dx}\text{ }=\text{ }\left( {{\mathbf{y}}^{\mathbf{3}}}-\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}\mathbf{y} \right)\text{ }\mathbf{dy},\]where c is a parameter.

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Which of the following differential equations has y = x as one of its particular solution? $(A)\frac{{{\partial }^{2}}y}{\partial {{x}^{2}}}-{{x}^{2}}\frac{dy}{dx}+xy=x(B)\frac{{{\partial }^{2}}y}{\partial {{x}^{2}}}+{{x}^{{}}}\frac{dy}{dx}+xy=x(C)\frac{{{\partial }^{2}}y}{\partial {{x}^{2}}}-{{x}^{2}}\frac{dy}{dx}+xy=0(D)\frac{{{\partial }^{2}}y}{\partial {{x}^{2}}}+{{x}^{{}}}\frac{dy}{dx}+xy=0$

= 0 – (x2 × 1) + (x × x) = -x2 + x2 = 0

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Form a differential equation representing the given family of curves by eliminating arbitrary constants a and b in \[\mathbf{y}\text{ }=\text{ }{{\mathbf{e}}^{\mathbf{x}}}~\left( \mathbf{a}\text{ }\mathbf{cos}\text{ }\mathbf{x}\text{ }+\text{ }\mathbf{b}\text{ }\mathbf{sin}\text{ }\mathbf{x} \right)\]

Differentiating both sides two times w.r.t.         [By eq. (i)]……….(ii) Again differentiating w.r.t. ,           [By eq. (i)]  

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Form a differential equation representing the given family of curves by eliminating arbitrary constants a and b in \[\mathbf{y}\text{ }=\text{ }\mathbf{a}{{\mathbf{e}}^{\mathbf{3x}}}~+\text{ }\mathbf{b}{{\mathbf{e}}^{-\mathbf{2x}}}\]

DifferentiatING both sides two times w.r.t.    ……….(ii) Again differentiating w.r.t. ,  ……….(iii) Multiplying eq. (i) by 3 and subtracting eq. (ii) from it, we get  ……….(iv) Again multiplying eq....

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Form a differential equation representing the given family of curves by eliminating arbitrary constants a and b in \[{{\mathbf{y}}^{\mathbf{2}}}~=\text{ }\mathbf{a}\text{ }({{\mathbf{b}}^{\mathbf{2}}}~-\text{ }{{\mathbf{x}}^{\mathbf{2}}})\]

Equation of the family of curves  ……….(i) Differentiating both sides two times w.r.t.     ……….(ii) Again differentiating w.r.t. ,   ……….(iii) Putting this value of  in eq. (ii), we get  ...

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verify that the given functions (explicit or implicit) is a solution of the corresponding differential equation: \[\mathbf{x}\text{ }+\text{ }\mathbf{y}\text{ }=\text{ }\mathbf{ta}{{\mathbf{n}}^{-\mathbf{1}}}\mathbf{y}\text{ }:\text{ }{{\mathbf{y}}^{\mathbf{2}}}~\mathbf{y}\prime \text{ }+\text{ }{{\mathbf{y}}^{\mathbf{2}}}~+\text{ }\mathbf{1}\text{ }=\text{ }\mathbf{0}\]

Differentiating both sides of eq. (i) w.r.t  we have     = eq. (ii) Hence, Function given by eq. (i) is a solution of 

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verify that the given functions (explicit or implicit) is a solution of the corresponding differential equation: \[\mathbf{y}\text{ }=\text{ }\mathbf{x}\text{ }\mathbf{sinx}\text{ }:\text{ }\mathbf{xy}\text{ }=\text{ }\mathbf{y}\text{ }+\text{ }\mathbf{x}\text{ }(\surd ({{\mathbf{x}}^{\mathbf{2}}}~-\text{ }{{\mathbf{y}}^{\mathbf{2}}}))\text{ }\left( \mathbf{x}\text{ }\ne \text{ }\mathbf{0}\text{ }\mathbf{and}\text{ }\mathbf{x}>\mathbf{y}\text{ }\mathbf{or}\text{ }\mathbf{x}<\text{ }\text{ }-\mathbf{y} \right)\]

 ..(ii)  =  L.H.S. of eq. (ii) =  R.H.S. of eq. (ii) =  =  [From eq. (i)] =  =  =  =  =  L.H.S. = R.H.S Hence,  given by eq. (i) is a solution of .

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verify that the given functions (explicit or implicit) is a solution of the corresponding differential equation: \[~\mathbf{y}\text{ }=\text{ }{{\mathbf{x}}^{\mathbf{2}}}~+\text{ }\mathbf{2x}\text{ }+\text{ }\mathbf{C}\text{ }:\text{ }\mathbf{y}\prime \text{ }\text{ }-\mathbf{2x}\text{ }\text{ }-\mathbf{2}\text{ }=\text{ }\mathbf{0}\]

Differentiating both sides with respect to x, we get, y’ = 2x + 2 Substituting the values of y’ in the given differential equations, we get, \[\begin{array}{*{35}{l}} =\text{ }y\text{ }-\text{...

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Determine order and degree (if defined) of differential equations given in \[{{\left( \mathbf{y”’} \right)}^{\mathbf{2}}}~+\text{ }{{\left( \mathbf{y”} \right)}^{\mathbf{3}}}~+\text{ }{{\left( \mathbf{y’} \right)}^{\mathbf{4}}}~+\text{ }{{\mathbf{y}}^{\mathbf{5}}}~=\text{ }\mathbf{0}\]

The highest order derivative present in the differential equation is  and its order is 3. The given differential equation is a polynomial equation in derivatives and the highest power raised to...

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