Evaluate the following value without using tables
(1) Find sin0 and cos0 , if tan0=1/3 , 0 does not belong to set [0,pi/2] .
(2) Find sin20 , if sin0+cos0=1/2 .
(3) Find 0 , if sin0.cos0=1/2sin0 , 0 does not belong to set [0,pi] .