Range is 1 because they all go up by 1
Answer:
a^2-1
Step-by-step explanation:
(a+1)(a-1)
=a^2-1
Answer:
Mean
Step-by-step explanation:
Given

Required
Best measure of center
The mean is considered the best measure of center when there are no outliers in the given data.
Outlier is when a particular data set is far away from other datasets.
For instance: 20 is an outlier in the following data sets: 
Also, the given data are not open-ended.
An open-ended data is as follows: 
Since we do not have any of the above conditions, then the mean is the best center to use.
Answer: Choice A. sin(A) = cos(B)
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Explanation:
The rule is that sin(A) = cos(B) if and only if A+B = 90.
Note how
- sin(A) = opposite/hypotenuse = BC/AB
- cos(B) = adjacent/hypotenuse = BC/AB
Since both result in the same fraction BC/AB, this helps us see why sin(A) = cos(B). Similarly, we can find that cos(A) = sin(B).
In the diagram below, the angles A and B are complementary, meaning they add to 90 degrees. So this trick only applies to right triangles.
The side lengths can be anything you want, as long as you're dealing with a right triangle.