Answer:
see explanation
Step-by-step explanation:
Using the Addition/ Subtraction formulae for cosine
Consider the left side
cos(x - y) - cos(x + y)
= cosxcosy + sinxsiny - (cosxcosy - sinxsiny) ← distribute
= cosxcosy + sinxsiny - cosxcosy + sinxsiny ← collect like terms
= 2sinxsiny = right side ⇒ proven
Answer:
243 ways
Step-by-step explanation:
Calculating the number of posible outcomes:
We have n trials.
Each trial has m possible outcomes.
The total number of outcomes is:

In this question:
5 questions, that is, 5 trials, so 
Each question has 3 options(True, false or unanswered). So 
How many ways?

Answer:
fr my account got banned 4 days ago i had to make a new one ppl keep reporting for fk reason smh
Step-by-step explanation:
" the quotient " means divide
(n/6) - 1 <== ur expression
It depends how high it is