Third graded homework (due 10/27)
For maximal credit, full working must be shown.

(3 points.)
Write the function
u(t) = 4 cos t  3 sin t
in amplitudephase form.

(4 points.)
Find a particular solution to the differential equation
y'' + y = csc t
for initial data at t = 1.

(4 points.)
Give the general solution to the differential equation
t^{2}y''  3ty' + 4y = 0
in the range t > 0. If you wish, you may assume that
y_{1}(t) = t^{2}
is one solution.
