Differential equations with laplace

dumbengineer
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Homework Statement



D^2 x -2x = 2sin2t x(0) = 0 , x'(0) = 1

Homework Equations



D^2 x = s^2ƒ[x] - sx(0) - x'(o)

The Attempt at a Solution



s^2ƒ[x] - sx(0) - x'(o) - 2ƒ[x] = 2sin2t

s^2ƒ[x] - sx(0) - x'(o) - 2ƒ[x] = 4 / s^2 + 4

ƒ[x] (s^2 + 1) + 1 = 4 / s^2 +4


ƒ[x] (s^2 + 1) = 4 / s^2 +4 - 1/s

i need help from here, i just keep messing up from this point and on, any help is greatly appreciated thanks !
 
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dumbengineer said:

Homework Statement



D^2 x -2x = 2sin2t x(0) = 0 , x'(0) = 1

Homework Equations



D^2 x = s^2ƒ[x] - sx(0) - x'(o)

The Attempt at a Solution



s^2ƒ[x] - sx(0) - x'(o) - 2ƒ[x] = 2sin2t

s^2ƒ[x] - sx(0) - x'(o) - 2ƒ[x] = 4 / s^2 + 4

ƒ[x] (s^2 + 1) + 1 = 4 / s^2 +4

Perhaps, being careful with your arithmetic and parentheses you mean
f[x](s2-2) -1 = 4/(s2+4)

Your careless use of parentheses may be causing additional errors in your next steps, which you didn't show.
 
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