Difference between revisions of "DVI exam"
(Created page with "==2022 222 problem 7== <cmath>r = 0.5, h = 3/2, KM = \frac {\sqrt{3}}{2},</cmath> <cmath>AM = KM \cdot \tan \alpha, BM = \frac {KM}{\tan \alpha} \implies AM + BM = AB</cmath>...") |
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==2022 222 problem 7== | ==2022 222 problem 7== | ||
+ | [[File:MSU 2022 2 7.png|400px|right]] | ||
<cmath>r = 0.5, h = 3/2, KM = \frac {\sqrt{3}}{2},</cmath> | <cmath>r = 0.5, h = 3/2, KM = \frac {\sqrt{3}}{2},</cmath> | ||
− | <cmath>AM = KM \cdot \tan \alpha, BM = \frac {KM}{\tan \alpha} | + | <cmath>AM = KM \cdot \tan \alpha, BM = \frac {KM}{\tan \alpha},</cmath> |
+ | <cmath>AM + BM = AB \implies</cmath> | ||
<cmath>\tan \alpha + \frac {1}{\tan \alpha} = 2 \sqrt {2} \implies \tan \alpha = \sqrt {2} - 1 \implies \tan 2 \alpha = 1 \implies 2 \alpha = \frac {\pi}{4}.</cmath> | <cmath>\tan \alpha + \frac {1}{\tan \alpha} = 2 \sqrt {2} \implies \tan \alpha = \sqrt {2} - 1 \implies \tan 2 \alpha = 1 \implies 2 \alpha = \frac {\pi}{4}.</cmath> |