`sin(u + v)` Find the exact value of the trigonometric expression given that sin(u) = -7/25 and cos(v) = -4/5 (Both u and v are in quadrant III.)

Expert Answers
gsarora17 eNotes educator| Certified Educator

Given `sin(u)=-7/25 , cos(v)=-4/5`

using pythagorean identity,


plug in the value of sin(u),








Since u is in Quadrant III ,


Now `sin^2(v)+cos^2(v)=1`

plug in the value of cos(v)=-4/5,






since v is in Quadrant III ,



plug in the values ,