Question

cos 18 °+ cos 162°+ sin 126° + sin 234°= ?​

Answer 1

Answer:

Step-by-step explanation:

cos 162 = cos( 180 - 18 )

cos 162 = - cos 18

sin 126 = cos( 90 + 36)

sin 126 = - cos 36

sin 234 = cos(270 - 36)

sin 234 = - cos 36

cos 18 - cos 18 - cos 36 -cos 36

-2cos 36

-2(0.8090)

-1.6180

Answer 2

Answer:

Step-by-step explanation:

Cos18 + Cos (180 - 162) + Sin126 + Sin(360 - 234)

Cos18 - Cos18 + Sin126 - Sin126 = 0