Answer: Choice B

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Explanation:
We'll be using the converse of the pythagorean theorem.
If we had a triangle with sides a,b,c and
was true, then we have a right triangle. Note: c is always the longest side
For the first answer choice we have: a = 5, b = 8, c = 12
Then,

which is false. This shows that we do not have a right triangle with sides 5,8,12. This rules out choice A. Choice C is a similar story.
Choice B on the other hand works because

We have a true statement at the end, which confirms <u>choice B</u> is a right triangle.
Answer:
6a-6b
Step-by-step explanation:
(5a+a)+(2b-8b)
6a-6b
None of these. All of these functions are defined as ratio of trigonometric functions.
Trigonometric functions have infinite zeroes, so when you put them in the denominator, they lead to infinitely many points of ill-definition.
Specifically, we have:

which is undefined at


which is undefined at


which is undefined at


which is undefined at
