Hii !

Prove That, by Use the defintion of a limit :

1) $\displaystyle \lim_{x\to 2} 2x-1 = 3$

2) $\displaystyle \lim_{x\to 0} \sin (\frac{1}{x})=0$

3) $\displaystyle \lim_{x\to 0} x^2 . E(\frac{1}{x})=0$