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MathNet 2015-part-01 — 191 problems (EN–VI) Question 143

Math Olympiad Vault · MathNet 2015-part-01 — 191 problems (EN–VI)

Question 143

In the drawing below, $ABCD$ is a rectangle and $E$ is the foot of the perpendicular drawn from $A$ to the diagonal $BD$. The distances from the point $E$ to the sides $DC$, $BC$ and $AB$ are $n$, $1$ and $x$, respectively. Let also $d$ be the length of the diagonal $BD$.
Question illustration

a) Verify that $DE = x^{2} \sqrt{1 + x^{2}}$.

b) Verify that $n = x^{3}$.

c) Verify that $d^{2/3} - n^{2/3} = 1$.