Classify the following function as injection, surjection or bijection :

$f:R\to R$, defined by $f\left(x\right)=\left|x\right|$

Classify the following function as injection, surjection or bijection :

$f:Z\to Z,$ defined by $f\left(x\right)=x^2+x$

Classify the following function as injection, surjection or bijection :

$f:Z\to Z$, defined by $f\left(x\right)=x- 5$

Classify the following function as injection, surjection or bijection :

$\mathrm{f}:\mathrm{ℝ}\to \mathrm{ℝ}$, defined by $\mathrm{f}\left(\mathrm{x}\right)=\mathrm{sinx}$

Classify the following function as injection, surjection or bijection :

$f:R\to R$, defined by $f\left(x\right)=x^3+1$

Classify the following function as injection, surjection or bijection :

$f:R\to R$, defined by $f\left(x\right)=x^3-x$

Classify the following function as injection, surjection or bijection :

$\mathrm{f} : \mathrm{ℝ}\to \mathrm{ℝ}$, defined by $\mathrm{f}\left(\mathrm{x}\right)={\sin }^2\mathrm{x}+{\cos }^2\mathrm{x}$

Classify the following function as injection, surjection or bijection :

$f:Q\to Q,$ defined by $f\left(x\right)=x^3+1$