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
Express each of the following as the product of sines and cosines:
sin 12x + sin 4x
Prove that:
cos A + cos 3A + cos 5A + cos 7A = 4 cos A cos 2A cos 4A
Prove that:
sin 3A + sin 2A − sin A = 4 sin A cos \[\frac{A}{2}\] \[\frac{3A}{2}\]
Prove that:
Prove that:
Prove that:
sin (B − C) cos (A − D) + sin (C − A) cos (B − D) + sin (A − B) cos (C − D) = 0
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 product of sine and cosine.
cos 2A + cos 4A
Prove that:
cos 20° cos 40° cos 80° = `1/8`
Prove that cos 20° cos 40° cos 60° cos 80° = `3/16`.
