Сегодня на кубке Колмогорова 🏆 прошли вторые туры матбоев. Присоединяйтесь к обсуждению матчей и задач в комментариях👇
Задача. Точки 𝐻 и 𝑂 – ортоцентр и центр описанной окружности остроугольного неравнобедренного треугольника 𝐴𝐵𝐶 соответственно. Точки 𝑃 и 𝑄 выбраны на описанной окружности 𝜔 так, что ∠𝐵𝑃𝐻 = ∠𝐶𝑄𝐻 = 90°. Пусть прямая 𝑃𝑄 пересекает касательную к 𝜔, проведенную в точке 𝐴, в точке 𝑆, а отрезки 𝑂𝑃 и 𝑂𝑄 пересекают отрезки 𝐵𝐻 и 𝐶𝐻 в точках 𝑋 и 𝑌 соответственно. Докажите, что 𝑂𝑆 ‖ 𝑋𝑌.
Сегодня на кубке Колмогорова 🏆 прошли вторые туры матбоев. Присоединяйтесь к обсуждению матчей и задач в комментариях👇
Задача. Точки 𝐻 и 𝑂 – ортоцентр и центр описанной окружности остроугольного неравнобедренного треугольника 𝐴𝐵𝐶 соответственно. Точки 𝑃 и 𝑄 выбраны на описанной окружности 𝜔 так, что ∠𝐵𝑃𝐻 = ∠𝐶𝑄𝐻 = 90°. Пусть прямая 𝑃𝑄 пересекает касательную к 𝜔, проведенную в точке 𝐴, в точке 𝑆, а отрезки 𝑂𝑃 и 𝑂𝑄 пересекают отрезки 𝐵𝐻 и 𝐶𝐻 в точках 𝑋 и 𝑌 соответственно. Докажите, что 𝑂𝑆 ‖ 𝑋𝑌.
Right now the digital security needs of Russians and Ukrainians are very different, and they lead to very different caveats about how to mitigate the risks associated with using Telegram. For Ukrainians in Ukraine, whose physical safety is at risk because they are in a war zone, digital security is probably not their highest priority. They may value access to news and communication with their loved ones over making sure that all of their communications are encrypted in such a manner that they are indecipherable to Telegram, its employees, or governments with court orders. "This time we received the coordinates of enemy vehicles marked 'V' in Kyiv region," it added. Russians and Ukrainians are both prolific users of Telegram. They rely on the app for channels that act as newsfeeds, group chats (both public and private), and one-to-one communication. Since the Russian invasion of Ukraine, Telegram has remained an important lifeline for both Russians and Ukrainians, as a way of staying aware of the latest news and keeping in touch with loved ones. The SC urges the public to refer to the SC’s I nvestor Alert List before investing. The list contains details of unauthorised websites, investment products, companies and individuals. Members of the public who suspect that they have been approached by unauthorised firms or individuals offering schemes that promise unrealistic returns Under the Sebi Act, the regulator has the power to carry out search and seizure of books, registers, documents including electronics and digital devices from any person associated with the securities market.
from ru
