As sinu=3/5sinu=35 and domain of uu is given by pi/2 < u < piπ2<u<π i.e. uu is in second quadrant and cosucosu is negative and
cosu=-sqrt(1-(3/5)^2)=-sqrt(1-9/25)=-sqrt(16/25)=-4/5cosu=−√1−(35)2=−√1−925=−√1625=−45
Further as cosv=-5/6cosv=−56 with pi < v < (3pi)/2π<v<3π2, hence vv is in third quadrant and sinvsinv is negative and
sinv=-sqrt(1-(-5/6)^2)=-sqrt(1-25/36)=-sqrt(11/36)=-sqrt11/6sinv=−√1−(−56)2=−√1−2536=−√1136=−√116
Now sin(u+v)=sinucosv+cosusinvsin(u+v)=sinucosv+cosusinv
= 3/5xx(-5/6)+(-4/5)xx(-sqrt11/6)35×(−56)+(−45)×(−√116)
= (-15)/30+(4sqrt11)/30−1530+4√1130
= (-15+4sqrt11)/36−15+4√1136
= (-15+4xx3.317)/36=-1.732/36=-0.0481−15+4×3.31736=−1.73236=−0.0481