Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Sum & Difference Identity: cos (A + B) = cos A · cos B - sin A · sin B
Recall the following from Unit Circle: cos (π/2) = 0, sin (π/2) = 1
cos (π) = -1, sin (π) = 0
Use the Quotient Identity: 
<u>Proof LHS → RHS:</u>




Quotient: tan x
LHS = RHS 
do you some help ?, I can try my best to help
Answer:
56%
Step-by-step explanation:
28/50=56/100
Since we know that a - 2 will equal 8, it is safe to assume that 8 + 2 = 10. Therefore a=10.