Question

Consider the following three functions:

1. $x^2$
2. $xcosx$
3. $e^x$

Which of them is a) An even function, b) AN odd function and c) neither an even or odd function?

Answer 1

1) Even. $(-x)^2=x^2$

2) Odd. $(-x)cos(-x)=-xcosx$

3) Neither. $e^{-x}\ne e^x,\;e^{-x}\ne -e^x$