The main identity you need is the double angle one for cosine:
We get
Expand the numerator to apply the identity again:
Finally, make use of the product identity for cosine:
so that ultimately,
Which expression simplifies to 2x^2y√5x
1 answer:
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Answer:
Divide the number you want to find the percentage for by the total amount of items in that group. Then, multiply that value by 100.
Step-by-step explanation:
Ex. There are 3 boys in a group of 4. What percentage of the group are boys?
75% of the group are boys