Question

prove that Sin 6x+ Sin 48-Sin 24 = 4 Cosx* Sin2x
•cos3x​

Answer 1

Answer:

L.H.S. =cosA−sinA+1cosA+sinA−1

=cotA−1+cosecAcotA+1−cosecA " " (divide each term of Nr. And Dr . By sin A)

(cotA cosecA)−1(cotA−cosecA)+1

=(cotA+cosecA)−(cosec2A−cot2A)(cotA−cosecA+1)(∵cosec2A−cot2A=1)

=(cosecA+cotA)(1−cosecA+cotA)(cotA−cosecA+1)

=(cosecA+cotA)(1−cosecA+cotA)(cotA−cosecA+1)

=cosecA+cotA=R.H.S.