For this case we have the following definitions:
A function is even if, for each x in the domain of f, f (- x) = f (x). The even functions have reflective symmetry through the y-axis.
A function is odd if, for each x in the domain of f, f (- x) = - f (x). The odd functions have rotational symmetry of 180º with respect to the origin.
We then have the following function:

Applying the definitions we have:

Answer:
The function is not odd because it is fulfilled:

Therefore, the function is even.
Answer:
D. -3x
Step-by-step explanation:
Terms have the form k or kx^n, where k is a number, x is a variable, and n is a whole number.
-3x follows the above rule, so -3x is a term.
Answer:
1) Is more representative
Step-by-step explanation:
The problem with his selection is that maybe there are few students participating in certain sport and those students maybe do quite more excercise than the rest (or quite less). This will modify the results because the sample he selected is biased. This problem wont be solved by method 3 or 4, because he is still selecting students that may modify heavily the results with a high probability
This problem will also appear if he choose a sample by class. Maybe, in a class there are quite few students, and selecting from class will make those students appear quite more often than, lets say, a 7th grade student selected at random, therefore the selection is biased in this case as well.
If he has a list with all seventh grade students, each student is equallly likely to be selected and as a consequence, the the results wont be biased. Approach 1 is the best one.
Answer:
The sum is equal to 
Step-by-step explanation:
we know that
The formula to calculate the sum is equal to

In this problem
-----> number of terms
a1 is the first term

an is the last term

substitute
