# Precalculus

posted by
**Lynette** on
.

1.Write the expression as a sum or difference.

cos(5x)cos(-4x)

2.Write the expression as a product.

cos(4x)-cos(12x)

posted by
**Lynette** on
.

1.Write the expression as a sum or difference.

cos(5x)cos(-4x)

2.Write the expression as a product.

cos(4x)-cos(12x)