Question

d^2y/dx^2 +19dy/dx +90y =0
The solution can be written in the form y=C1f1(x) +C2f2(x)
with f1(x)= ? and f2(x)= ?

Answer 1

I'm getting that f1 should be e^(-9x) and f2 should be e^(-10x)
which is not correct

Answer 2

try without the minus signs

Answer 3

then you have 9 + 10 = 19, and 9 x 10 = 90

Answer 4

no your quite right sorry

Answer 5

nevermind for some reason webwork wasn't taking my answer but it finally did. Thanks for your help anyways :)

Answer 6

auxillary equation will be (J + 9)(J + 10), making the answer C(e^-9x) + D(e^-10x) with C and d constants

Answer 7

yeah sorry

Answer 8

Just learning about this method myself atm. :)