Question

evaluate

1) cos 38 cos 52- sin 38 sin 52

2) 5 cos2 60 + 4 sec2 30 - tan2 45

sin2 30 + cos 2 30

Answer 1

hey friend here is your answer
1.cos(38+52)
=cos90=0
2.5×(1/2)2+4(2/√3)2-1
=5/4+4×4/3-1
=5/4+16/3-1
=15+64-12/12
=67/12
3.(1/2)2+(√3/2)2
=1/4+3/4=1
Hope it will help you