Get Answers to all your Questions

header-bg qa

If y = y(x) is the solution of the differential equation, x\frac{dy}{dx} +2y = x^2 satisfying y (1) =1 then y\left(\frac{1}{2} \right ) is equal to 

  • Option 1)

    \frac{7}{64}

  • Option 2)

    \frac{1}{4}

  • Option 3)

    \frac{49}{16}

  • Option 4)

    \frac{13}{16}

Answers (1)

best_answer

 

Linear Differential Equation -

\frac{dy}{dx}+Py= Q

- wherein

P, Q are functions of x alone.

 

 

Linear Differential Equation -

Multiply by e^{SPdx}  which is the Integrating factor

- wherein

P is the function of x alone

Differential Equation can be written as.

\frac{\mathrm{d} y}{\mathrm{d} x}+2\left ( \frac{y}{x} \right )=x

from the concept we have learnt 

\frac{\mathrm{d} y}{\mathrm{d} x}+P(x)\cdot y=Q(x)

If = e^{\int P\cdot dx}=x^{2}

Solution of this d.e is 

Y(IF)=\int Q\left ( IF \right )dx+C

So, \therefore yx^{2}=\frac{x^{4}}{4}+C

given y(1)=1

1=\frac{1}{4}+C\Rightarrow C=\frac{3}{4}

y\left ( x^{2} \right )=\frac{x^{4}}{4}+\frac{3}{4}

We need to find y\left ( x=\frac{1}{2} \right )

Put x=\frac{1}{2}

\frac{y}{4}=\frac{1}{64}+\frac{3}{4}

y=\frac{49}{16}

 


Option 1)

\frac{7}{64}

Option 2)

\frac{1}{4}

Option 3)

\frac{49}{16}

Option 4)

\frac{13}{16}

Posted by

admin

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE