Product of Trigonometric Ratios in Terms of Their Sum
2 sin 2β+4 co...
Question
2sin2β+4cos(α+β)sinαsinβ+cos2(α+β)=
A
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is C cos2(α+β)=2cos2(α+β)−1,2sin2β=1−cos2β L.H.S. =−cos2β+2cos(α+β)[2sinαsinβ+cos(α+β)] =−cos2β+2cos(α+β)cos(α+β) =−cos2β+(cos2α+cos2β)=cos2α.