Into Function

Q. Which of the following functions are into functions if they are all defined from $R$ to $R$?

1. $f\left(x\right)=\text{sin}x$
2. $f\left(x\right)=\text{cos}x$
3. $f\left(x\right)=e^x$
4. $f\left(x\right)=x^3$

Q. $\mathrm{If}f:A\to B\mathrm{is}a\mathrm{constant}\mathrm{function},\mathrm{then}\mathrm{range}\mathrm{of}f\mathrm{will}\mathrm{have}\mathrm{\_\_\_}\mathrm{elements}$

1. 1
2. Infinite
3. 0
4. 2

Q.

Function f(x) = {x} on f: R $\to$ R where {} is fractional part function, is an into function.

1. True

2. False