If sinA=12/13 & tan B=3/4 then find

Question

If sinA=12/13 & tan B=3/4 then find 
                       ¡= sin(A+B)
                      ¡¡=COS(A-B)
                     ¡¡¡=COT(A-B)
                      ¡v=cot(A-B)
Sir please give me the correct ans because tomorrow is my class

Reiny · Accepted Answer

for sinA = 12/13, we have the 5-12-13 triangle,
so cosA = 5/13
and tanA= 12/5

for tanB = 3/4, we have the 3-4-5 triangle,
so sinB = 3/5
and cosB = 4/5

you have to know the expansion formulas, I will do the first one, you do the rest

sin(A+B) = sinAcosB + cosAsinB
= (12/13)(4/5) + (5/13)(3/5)
= 48/65 + 15/65 = 63/65

always check with a calculator, my answer is correct

I noticed your last two questions are the same, watch for a typo