- #1
cue928
- 130
- 0
I am to find a general solution of the system of problems below. I have done so for x(t) but am unsure how to find it for y(t)...
x'=y, y'=-x
x''=y=-x
x''+x=0
Characteristic eq: r^2 + 1= 0, r = +/- i
x(t) = A cos(t) + B sin(t)
How do I go about calculating y(t), which th book shows as being y(t)=B cos(t)+Asin(t)
Similarly, I calculated x(t)=A cos (2t) + B sin(2t), but am unsure how to get the book's version of y(t)=4B cos 2t - 4A sin(2t)
x'=y, y'=-x
x''=y=-x
x''+x=0
Characteristic eq: r^2 + 1= 0, r = +/- i
x(t) = A cos(t) + B sin(t)
How do I go about calculating y(t), which th book shows as being y(t)=B cos(t)+Asin(t)
Similarly, I calculated x(t)=A cos (2t) + B sin(2t), but am unsure how to get the book's version of y(t)=4B cos 2t - 4A sin(2t)