Therefore, {{MATH_331}} and {{MATH_332}} Now, we {{CMD_333}}differentiate{{CMD_334}} with respect to {{MATH_335}}. {{MATH_336}} This equation holds over some time interval. In particular, the equation is true at time when {{MATH_337}} cm. Now we {{CMD_338}}evaluate{{CMD_339}} all the quantities at that time. {{MATH_340}} So, at the instant when the water in the container is {{MATH_341}} cm deep, the water level is rising at the rate of {{MATH_342}} cm/s. {{CMD_343}} {{CMD_344}} {{CMD_345}}