Advertisements
Advertisements
प्रश्न
Express the following as the sum or difference of sine or cosine:
`cos (7"A")/3 sin (5"A")/3`
Advertisements
उत्तर
`= 1/2 [2 cos (7"A")/3 sin (5"A")/3]` ...[Multiply and divide by 2]
`= 1/2 [sin ((7"A")/3 + (5"A")/3) - sin ((7"A")/3 - (5"A")/3)]`
`= 1/2 [sin (12"A")/3 - sin (7"A" - 5"A")/3]`
`= 1/2 [sin 4"A" - sin (2"A")/3]`
APPEARS IN
संबंधित प्रश्न
Prove that:
sin 38° + sin 22° = sin 82°
Prove that:
sin 40° + sin 20° = cos 10°
Prove that:
sin 50° − sin 70° + sin 10° = 0
Prove that:
cos 3A + cos 5A + cos 7A + cos 15A = 4 cos 4A cos 5A cos 6A
Prove that:
Prove that:
If \[m \sin\theta = n \sin\left( \theta + 2\alpha \right)\], prove that \[\tan\left( \theta + \alpha \right) \cot\alpha = \frac{m + n}{m - n}\]
If cos A = m cos B, then write the value of \[\cot\frac{A + B}{2} \cot\frac{A - B}{2}\].
Express the following as the sum or difference of sine or cosine:
cos(60° + A) sin(120° + A)
Evaluate-
cos 20° + cos 100° + cos 140°
