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Pepsi24chevy
Dec1-04, 01:56 PM
Hey guys, the problem reads: Find the values of k for which y=x^2+k i sa solution to the differenital equation: 2y-xy`= 10. Anyways I am confused on how to set this up. DO i keep taking the derivative of the dif equation and plugging is back into the first one or what. :redface:

arildno
Dec1-04, 02:05 PM
1) Compute y' from your given expression for y(x)
2) Insert the given expressions for y and y' into the expression making the left-hand side of the differential equation.
3) Determine the value(s) of "k" so that what you got in 2) equals 10.

Pepsi24chevy
Dec1-04, 02:27 PM
Thanks. So i got y`= 2x+1 so then i plug then info i have into the differential equation so that i get 2(x^2+1) - x(2x+1) = 10. Now i am still not quit sure how to determine K. Also is the deriviative of the K constant 1?

vladimir69
Dec1-04, 03:24 PM
the derivative of a constant is 0