- #1

fufufu

- 17

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## Homework Statement

y'' + 4y = sin(2t)

y(0) = 1

y'(0) = 1

## Homework Equations

cramers rule

## The Attempt at a Solution

after isolating Y(s) i end up with:

Y(s) = 2 / (s^2+4)^2 + s/(s^2+4)

after i do partial fraction decomposition, i get 4 equations with 4 unknowns, A, B, C and D

i inserted B = 2- 4D into other 3 equations..

when i used cramers rule to get values for A , B and C I am getting zeroes for all three variables. (??) ..also, I noticed that each equation also equals zero, but I am not seeing what that might mean?

i am doing something wrong

my 3 equations are:

A + 5C + D = 0

-A -5C + D = 0

2A + 16C -4D = 0

any help is really appreciated...thanks

## Homework Statement

## Homework Equations

## The Attempt at a Solution

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