Express each of the following as a product.
1. sin 10x + sin 6x
2. sin 7x – sin 3x
3. cos 7x + cos 5x
4. cos2x – cos 4x
1. = 2
=2
=2
Using,
sin( A +B)= sinA cos B + cosA sinB
= 2
= 2
= 2cos5x sin2x
Using,
sin( A - B)= sinA cos B - cosA sinB
= 2
= 2
= 2
Using,
cos (A + B) = cosAcosB – sinAsinB
4.= -2
= -2
= 2sin3x sinx
Using,
cos (A - B) = cosAcosB+ sinAsinB