solve the differential equation dy/dx=(3x*exp(4y))/(7+(2x^(2))^(2) when y = 0, x = 2

Move y terms to the left hand side and the keep the x terms on the right hand side: dy*(1/(exp(4y))) = dx*(3x/(7+2x^(2))^(2))
First, solve the right hand side by using a substition: u = 7 + 2x^(2), du/dx=4xFrom that the integral goes to (3/4)(u^(-2))du = -(3/4)(u^(-1)) + C = - ( 3/4)(1/(7+2x^(2))) + C
Second, solve the left hand side: dy
(1/(exp(4y))) = dy*(exp(-4y)) = -(1/4y)exp(-4y)
exp(-4
0) = 1 = (3)(1/(7+2^(3))) + C, rearrange to find C = 1/5
So, exp(-4y) = 3/(7+2
x^(2)) + 4/5,
y = -(1/4)ln((3/(7+2x^(2))) + 4/5) = ln((3/(7+2*x^(2))) + 4/5)^(-1/4)

Related Maths A Level answers

All answers ▸

For a curve of gradient dy/dx = (2/(x^2))-x/4, determine a) d^2y/dx^2 b) the stationary point where y=5/2 c) whether this is a maximum or minmum point and d) the equation of the curve


Integrate exp(2x)cos(8x) by parts


Differentiate the following... f(x)= 5x^4 +16x^2+ 4x + 5


Find the area enclosed by the curve y = 3x - x^2 and the x-axis