Question
Mathematics Question on Trigonometric Identities
If a=cos2α+isin2α and b=cos2β+isin2β then _______
A
ab=cos(α+β)−isin(α+β)
B
ab=cos(α+β)+isin(α+β)
C
ab=sin(α+β)+icos(α+β)
D
ab=sin(α+β)−icos(α+β)
Answer
ab=cos(α+β)+isin(α+β)
Explanation
Solution
The correct answer is(B): ab=cos(α+β)+isin(α+β)