Question

Calcule :
A)cos 1560°
B)cos 1035°
C)cos (-270°)​

Answer 1

Question.....

1. cos(1560°)

cos(4×360°+120)

cos(120°)

cos(90°+30°)

-sin30°

- 1/2

2.Question

cos(1035)

cos(2×360°+315)

cos315°

cos(360°-45)

cos45°

1/√2

Question...

cos(-270)

cos270°

cos(180°+90°)

-sin90°

-1

This is your answer