The required steps that complete the proof are:
Step 1: Cofunction Identity
Step 5: Sine Difference Identity
Step 6: Cofunction Identity
Step 7: Cosine Function Is Even, Sine Function Is Odd
<h3>Trigonometry identity</h3>
Given the cosine function expressed as:
The first step is to apply the cofunction identity as shown:
- Step 1: Cofunction Identity
cos(90 - x) = sin x
cos(x - y) = sin (90-(x-y))
- Step 5: Sine Difference Identity
For the fifth step, you will apply the sine difference identity.
- Step 6: Cofunction Identity
To get the sixth step, you will apply the Cofunction Identity on the result in the fifth step.
The final step 7 will be
- Step 7: Cosine Function Is Even, Sine Function Is Odd
Learn more on trigonometry identity here: brainly.com/question/24496175