Show that:
(sin 3x+sin x)sin x + (cos 3x-cos x)cos x =0
Answers
Answered by
1
Step-by-step explanation:
this is your answer please check out
Attachments:
Answered by
1
Answer :
Now,
(sin3x + sinx) sinx + (cos3x - cosx) cosx
= sin3x sinx + sin²x + cos3x cosx - cos²x
= (cos3x cosx + sin3x sinx) - (cos²x - sin²x)
= cos(3x - x) - cos2x
= cos2x - cos2x
= 0
Hence, proved.
Trigonometric Identities :
cos(A - B) = cosA cosB + sinA sinB
cos2A = cos²A - sin²A
#MarkAsBrainliest
Similar questions