Answer:
See below.
Step-by-step explanation:

First, use the co-function identity:

We can turn the second term into cosine:

Substitute:

Now, use the sum to product formulas. We will use the following:

Substitute:

Use the even-odd identity:

Therefore:

Replace the second term with the original term:

Proof complete.
Answer:
i have a Similar question I’m stuck on, just remember z rule, vertically opposite etc.
Answer:
37 degrees
Step-by-step explanation:
1. m∠CBA = 71+45 = 116 degrees
2. m∠CBA = m∠CDA because of the quadrilateral property of opposite sides.
3. m∠CBA + m∠CDA = 2*116 = 232.
4. Total angle measure of a quadrilateral is 360 degrees, so m∠BAD + m∠BCD = 360-232 = 128 degrees.
5. m∠BAD = m∠BCD = 128/2 = 64 degrees
6. m∠BAC = m∠BAD - m∠CAD = 64 - 27 = 37 degrees
Factorize the sum of cubes:

so
is a factor of
. Then the HCF is
.