Original
A rectangle is inscribed in the ellipse
{{MATH_1}}
so that two of its edges are parallel to the {{MATH_2}}-axis, and the other two are parallel to the {{MATH_3}}-axis.
Find the dimensions of the rectangle with the largest area.
{{CMD_4}}
{{CMD_5}}
{{ENV_6}}
{{CMD_7}}
{{CMD_8}}
{{CMD_9}}
Area of the rectangle
{{MATH_10}}.
We will express {{MATH_11}} as a function of, say, {{MATH_12}}.
Note that {{MATH_13}} and {{MATH_14}} satisfy the equation of the ellipse, so
{{MATH_15}}
Since in our figure {{MATH_16}}, we have
{{MATH_17}}
{{CMD_18}}
{{CMD_19}}
Now
{{MATH_20}}.