CPM Homework Help : CALC Problem 2-105

Without your graphing calculator, determine if the following functions are even, odd, or neither. Explain how you determined your choice. Then, check your answer with your graphing calculator.

$y =\operatorname{cos}(3x)$
Hint (a):
You should know by now that $y =\operatorname{cos}x$ is an even function. But what about $y =\operatorname{cos}(3x)$ ? What does the $3$ do to the parent graph?

$y = - | 2 x |$
Hint (b):
Compare to $y = |x|$ .

Compute without a calculator