On the interval {{MATH_13}} {{MATH_14}} is {{CMD_15}}{{CMD_16}}increasing{{CMD_17}}{{CMD_18}}decreasing{{CMD_19}}{{CMD_20}}not defined{{CMD_21}}{{CMD_22}} and {{CMD_23}}{{CMD_24}}concave up{{CMD_25}}{{CMD_26}}concave down{{CMD_27}}{{CMD_28}}not defined{{CMD_29}}{{CMD_30}}.