Given: sin(x - y) 1. - cos[7 (x-]
2. =cos[ī - (x+v]
3. =cos[(1 - x) +v]
4. = cos[( 1 - x)-(-v]
5. = cos(1 - x) cos(-x)+ sin( 1 - x) sin (-1)
6. = sin(x)cos(-y) + cos(x)(sin(-y)
7 = sin(x)cos(y) - cos(x)sin(y)
Choose a justification for each step in the derivation of
the sine difference identity.
Step 1:
Step 2: Distributive property
Step 3: Associative property
Step 4: Factoring out-1
Step 5
Step 6:
Step 7