Give the general solution to the Ordinary Differential Equation: (dy/dx) + 2y/x = 3x+2

It can first be observed that this differential equation is linear, so we can solve it by multiplying the whole equation by the integrating factor. As there is no coefficient in front of the dy/dx term, we do not have to do anything to the equation before finding the integrating factor. The integrating factor is exp( integral (2/y) dx). From core maths we can solve this; the integral gives 2 ln (x). 2 ln (x) is equal to ln (x^2) using the rules of exponentials. exp ( ln(x^2) ) is x^2 and so the integrating factor is x^2.
We then multiply the equation by the integrating factor, x^2, to get x^2*(dy/dx) + 2xy = x^2(3x+2). We can recognise the left hand side as the product rule and so we can express the equation as: d(x^2y)/dx = 3x^3 + 2x^2. This is now separable and so we can use techniques learned from the maths a level to give: x^2y = 0.75x^4 + (2/3)x^3 + c, making sure to add the + c as it is the constant of integration. Dividing through by x^2 we get y = 0.75x^2 + 2x/3 + c/x^2. This is the general solution to the differential equation.

VG
Answered by Veer G. Further Mathematics tutor

5502 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

Use De Moivre's Theorem to show that if z = cos(q)+isin(q), then (z^n)+(z^-n) = 2cos(nq) and (z^n)-(z^-n)=2isin(nq).


Show that the matrix A is non-singular for all real values of a


Use de Moivre’s theorem to show that, (sin(x))^5 = A sin(5x) + Bsin(3x) + Csin(x), where A , B and C are constants to be found.


Find the integral of f(x)= x^3 + 2x^2 + 1


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning