Angle a lies in the second quadrant and angle b lies in the third quadrant such that cos(a)=-3/5 and tan(b)=24/7. Determine an exact value for

Question

a) cos(a+b)
b) sin(a-b)
c) sin2a

Answer 1

a) cos(a)cos(b) + sin(a)sin(b)

find sin ratio: use pythagorus (5^2) - (-3^2) = #. Sin = y/r = #/r.

then solve a)

Answer 2

question ( c)

Answer 3

please atemt question (c)

Answer 4

Yes