Suppose that p and q are continuous on some open interval I and suppose that y1 and y2 are solutions o the ode
y''+(t)t'+q(t)y=0
a. Suppose that y1 , y2 is a fundamental set of solutions. Prove that z1, z2 given by z1=y1+y2, z2=y1-y2 is also a fundamental set of solutions.
b. prove that...