Question

find the value of cos 165°​

Answer 1

Step-by-step explanation:

Use the cosine angle addition formula. 

cos(165°)

= cos(120° + 45°)

= cos(120°)cos(45°) - sin(120°)sin(45°)

= (-1/2)(√2/2) - (√3/2)(√2/2)

= -√2/4 - (√3√2)/4

= -√2/4 - √6/4

= (-√2 - √6)/4 

Therefore, cos(165°) = (-√2 - √6)/4. 

hope it helps and pls mark me as brainliest and pls follow me

▪︎■♡■▪︎