Congruent means they are the same size
To prove the two triangles are congruent you would need to know the length of at least two of the sides. If two sides were not known you would need to know the length of one side and at least one of the unknown angles.
a. Recall that
For , we have
By integrating both sides, we get
If , then
so that
We can shift the index to simplify the sum slightly.
b. The power series for can be obtained simply by multiplying both sides of the series above by .
c. We have
Answer:

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Answer:
a =6
b=4
c=2
step-by-step explanation:
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=
= 