Use The identities for sin (a + B) and sin {ct [3) to subtract the left and right sides of the identities and derive the product-tosum formula for cos or sin [3. Begin by writing the dierence and sum formulas for sine. sin[u+|3]l=|: sin[u|3].=|: New subtract the second identity from the rst. sina+u} sin[u:|3}=|: Use This result to derive the product-td-sum formula for cos a sin [3. Reverse the side in the preceding equation. (Simpliiy your answer.) 1 Divide each side by E" 1 Multiply each side by E