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To solve for the original equation, we're going to take
the integral four times, so the integral of Y to the four TT
equaling the integral of the quantity -4 sine t + 2 cosine
TDT.
We're going to get Y to the third prime equal 4 cosine t + 2
sine t + C one.
Sticking in the original .0 for T and 10 for Y triple prime, we
get 10 equal 4 cosine 0 + 2 sine 0 plus C1.
Cosine of 0 is 1, sine of 0 is 0, so we get C1 being 6.
Now we're going to take the integral of the Y triple prime
DT equaling the integral of four cosine t + 2 sine t + 6 DT.
So Y double prime equals 4 sine t - 2 cosine t + 6 T plus C2.
Now going up and looking at what our Y double prime was, we were
know T is 0 when Y double prime is -2 so -2 equal 4 sine 0 - 2
cosine 0 + 6 * 0 plus CT suit C sub two.
So C sub two is going to be zero.
We're going to take and do the integral again.
We're going to get Y prime equaling -4 cosine T -2 sine T
plus three, t ^2 + C sub three.
Going back to the original, we know that T is 0 when Y prime is
-4.
So solving we get C sub three equaling 0.
Doing the integral one more time, we get Y equal -4 sine t +
2, cosine t + t ^3 + C four.
Going back to the original, we know that when T is 0, our
original Y is -1.
Plugging that in, we get our C4 being -3 for a final answer of Y
equal -4 sine t + 2, cosine t + t ^3 -, 3.