Question

Given sin A=2/3 and cos B = -1/2 where A is in quadrant 2 and B is in Quadrant 3 find

Sin(A+B), cos (A-B), and tan(A-B)

Answer 1

\[\sin(A+B)=\sin(A)\cos(B)+\sin(B)\cos(A)\]plug in the numbers

Answer 2

you know
\[\sin(A)=\frac{2}{3}\] do you know how to find
\[\cos(A)\]?

Answer 3

I don't, I miss class the day they went over this!!

Answer 4

draw a right triangle with an angle \(A\) make the opposite side of the angle 2, and the hypotenuse 3

Answer 5

use pythagoras to find the missing sides
let me know what you get

Answer 6

if it is not clear let me know an i can show you