Original
We measure that the edge length of a cube is {{MATH_1}}.
However, our ruler only allows us an accuracy of {{MATH_2}}. Use differentials to estimate the potential error in the
surface area which results from this potential error in measurement.
{{CMD_3}}
The surface area of the cube, {{MATH_4}}, is a function of the edge length {{MATH_5}}:
{{MATH_6}}.
{{CMD_7}}
{{CMD_8}}
We have to compute the differential of {{MATH_9}} at {{MATH_10}}.
{{MATH_11}}.
{{CMD_12}}
{{CMD_13}}
First, we have compute the derivative of {{MATH_14}}.
{{MATH_15}}.
{{CMD_16}}
{{CMD_17}}
Now we compute the the differential of {{MATH_18}} at {{MATH_19}}.
{{MATH_20}}.
{{CMD_21}}
{{CMD_22}}
We have to determine {{MATH_23}}.
{{MATH_24}}.
{{CMD_25}}
{{CMD_26}}
The potential error when we compute the surface area based on the measurement of the edge length is then given by
{{MATH_27}}.
{{CMD_28}}
{{CMD_29}}
The potential error is {{MATH_30}}
{{CMD_31}}