# Q1 prove thatcos1cos 2 cos 3 ....... cos 180 = 0 q2evaluate tan 5 tan 25 tan 30 tan 65 tan 85

1
Log in to add a comment

Log in to add a comment

cos1 x cos2 xcos3 x............x 0 x..........x cos180

0

hence proved.

Q2 ; tan5 x tan25 x tan30 x tan65 x tan85

tan5 x tan25 x tan30 x tan(90-25) x tan(90-5)

1/cot5 x 1/cot25 x tan30 x cot25 x cot5

1 x 1 x tan30

tan30 or 1/root 3