Question

Evaluate: 5 cos 55/7 sin 35 - 4 cos 70 cosec 20/7(tan5 tan25 tan45 tan65 tan85)

Answer 1

Heya....  = 3 cos 55/7 cos 55 - (4 cos 70/ sin 20) /7 tan 5 cot(90-85) tan 25 cot(90-65) tan 45 = 3/7 - (4 cos 70 / cos 70)/ 7 tan 45 = 3/7 - 4/7 = -1/7   @skb