If cos a b 4 5
- If cos a 3 cos b 4 1 5
- If cos a 4 5 cos b 12 13
- If a 5 b 4 cos ab )= 31 32
- If a 6 b 3 and cos ab )= 4 5
- If sin a 4 5 and cos b 12 13
- If x 2 5 2x 4 cos a b
- If a 4 b 5 c 7 find cos b 2
- If sin a 4 5 and cos b
- If cos a 4 5 cosb 3 5 find a b c
- If 0 a b π/4 and sin(a+b)=24/25 and cos(a-b)=4/5 then find the value of tan2a