Question

what is the value of cos( 60° + theta ) + cos( 60° - theta )​

Answer 1

Answer:

Step-by-step explanation:

tan theta = cot (60+theta)

cot (90-theta) = cot (60+ theta)

if angles are same then they r equated

90-theta = 60 + theta

90-60 = theta + theta

30 = 2 theta

theta = 15 °