Question

Which of the following functions are even and which are odd?

1) $f\left(x\right)=x^2+7$

2) $f\left(x\right)=x+2$

3) $f\left(x\right)=x^7+2x^5$

4) $f\left(x\right)=\left|x\right|+4$

Answer 1

When $f\left(x\right)=f(-x)$, function is even

$f\left(x\right)=-f(-x)$, function is odd

(A)

$f\left(x\right)=x^2+7$

$f(-x)=x^2+7$ - Even

(B)

$f\left(x\right)=x+2$

$f(-x)=-x+2$ - Neither even nor odd

(C)

$f(-x)=x^7-2x^5$

$f\left(x\right)=-x^7-2x^5$- odd

(D)

$f\left(x\right)=|x|+4$

$f(-x)=|x|+4$ - Even