Question

Cos pi/4 cos pi/6=1/2(__pi/12+cos5pi/12)

Fill in the ___

Answer 1

2 (1/√2) (√3/2) = cos(5π/12) + cos(π/12)

√3/2 = 1/2 (cos(5π/12) + cos(π/12))

Therefore, the missing term is "cos(π/12)".

Hence, the complete equation is:

cos(π/4) cos(π/6) = 1/2 (π/12 + cos(5π/12))