Let f (x) and G (x) be bounded on D. It is proved that f (x) + G (x), f (x) - G (x), f (x) * g (x) are also bounded on D There is another proof that the function y = xsinx is unbounded on (0, + 8), that, + 8 is positive infinity

Let f (x) and G (x) be bounded on D. It is proved that f (x) + G (x), f (x) - G (x), f (x) * g (x) are also bounded on D There is another proof that the function y = xsinx is unbounded on (0, + 8), that, + 8 is positive infinity

① Let f (x), G (x, G (x) be bounded on D, and there are positive real numbers m (1) and m (2) such that \\\124\124\124\124\124\\124\\124\\\\\\\ (x) \\\124\\ (x (x) \\theoremf (x (x (x (x (x (x (x (x (x (x (x (x), G (x, G (x), G (x, G (x, G (x), G (x (x (x), G (x on