Question

cos 28 + sin28 =k cube then cos 17​

Answer 1

Answer:

Cos28 + Cos(90-28) = k cube 

Cos28 + Cos62 =k cube 

Using CosC +CosD= 2Cos(C+D)/2×Cos(C-D)/2 ,              *divide the value of the angle by 2

2Cos45×Cos17=k cube

Root 2 × Cos17= k cube                                                         Cos 17 = k cube/ root 2