NostradamusEstrademe
JF-Expert Member
- Jul 1, 2017
- 3,869
- 5,170
Prove that
1.sinA+sinB=2cos (A-B/2)×sin (A+B/2)
2.cos2X=cos^2 X-sin^2 X
3.cos^2 X+sin^2 X =1
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1.sinA+sinB=2cos (A-B/2)×sin (A+B/2)
2.cos2X=cos^2 X-sin^2 X
3.cos^2 X+sin^2 X =1
Sent using Jamii Forums mobile app