For any two real numbers 55', y, consider Iircl lyii (III + 1)(|y| +1)' Show that (R, d) is metric space by checking all properties of a metric space are satised. - . - lIil i _ l 1 II? - r Hint. Notice that (|I|+1](|:i+13 |y|y+l \"1+1, why does this help! dbl, y) =