Correct Answer - B
We have,
`sin theta=1/2and cos phi=1/3`
`impliescostheta=(sqrt3)/(2)and sin phi=(2sqrt2)/(3)`
Now, `sin(theta+phi)=sinthetacosphi+costhetasinphi`
`sin(theta+phi)=1/6+sqrt((2)/(3))=0.1.66+0.816=0.982`
`impliestheta+phi"is in hte neighbourhood of"(pi)/(2).`
Also, `sintheta=1/2impliestheta=(pi)/(6)and, cosphi=1/3implies(pi)/(3)ltphilt(pi)/(2)`
`thereforetheta+phigt(pi)/(2).`
Hence, `theta+phiin((pi)/(2),(2pi)/(3)]`
