On the interval {{MATH_337}}, the derivative {{MATH_338}} does not change the sign. Since {{MATH_339}}, {{MATH_340}} is {{CMD_341}} {{CMD_342}}increasing{{CMD_343}} {{CMD_344}}decreasing{{CMD_345}}{{CMD_346}} on {{MATH_347}}. {{CMD_348}} {{ENV_349}} {{COMMENT_350}} {{COMMENT_351}} {{CMD_352}} The second derivative of {{MATH_353}} on {{MATH_354}} is {{MATH_355}}