for all {{MATH_58}} in {{MATH_59}}. {{CMD_60}} Since {{MATH_61}} on {{MATH_62}}, the function {{MATH_63}} is increasing on the interval {{MATH_64}}. {{CMD_65}} {{CMD_66}} Since the function {{MATH_67}} is increasing (and continuous on {{MATH_68}}) on the interval {{MATH_69}}, it follows that