Prove that Sin (4pi/9 + 7) Cos (pi/9 + 7) - Cos (4pi/9 + 7) Sin (pi/9 + - Maths - Trigonometric Functions

Question

Prove that Sin (4pi/9 + 7) Cos (pi/9 + 7) - Cos (4pi/9 + 7) Sin
(pi/9 + 7) = Root3/2

Nazmin Hussain · Accepted Answer

Here is the proof :- (Open the image👇)
<img src=
"https://s3mn%20mnimgs%20com/img/shared/content_ck_images/ana_qa_image_57a5c130853cb%20jpeg">

Prove that Sin (4pi/9 + 7). Cos (pi/9 + 7) - Cos (4pi/9 + 7). Sin (pi/9 + 7) = Root3/2