Question

Evaluate the given function sin(A +B) by using the following information: sin A= 4/5 (1st Quad.) and cos B= -12/13 (2nd Quad.)

Answer 1

sin(A+B) = sin A cos B + sin B cos A
sin (A + B) = (4/5)(-12/13) + (5/13)(3/5)+
= -48/65 + 15/65
= -33/65

Answer 2

Keep in mind that:

If sin A = 4/5 then cos A = 3/5 just draw a right triangle, it is a 3-4-5 right triangle

The other triangle is a 5-12-13 right triangle

Answer 3

Any questions?

Answer 4

Oh, Thanks so much!