1. Show that this is an identity by using the definitions of the sum and difference formulas for cosine: sin a sin b = =[cos(a - b)- cos(a + b)] Complete the left-hand column of the table below following the steps indicated in the right-hand column. (12 points) Calculation Reason Given on the right side of the [cos(a - b) -cos(a+ b)] original problem Apply the definitions of the sum and difference identities for cosine Simplify the expressions 2. Use the subtraction formula for sine to verify this identity: sin - x = COSX Complete the two columns of the table below to demonstrate that this is an identity. (12 points) Calculation Reason Given on the left side of the sing - x original