8...

kseniyatyutrina @kseniyatyutrina

July 2022 1 5 Report

докажите справедливость равенства: cosп/7cos2п/7cos4п/7=-1/8

Answers & Comments

irkarom

$cos\frac{\pi}{7}cos\frac{2\pi}{7}cos\frac{4\pi}{7}=$

умножим и поделим на $8sin\frac{\pi}{7}$

$cos\frac{\pi}{7}*cos\frac{2\pi}{7}*cos\frac{4\pi}{7}=\frac{8sin\frac{\pi}{7}*cos\frac{\pi}{7}*cos\frac{2\pi}{7}*cos\frac{4\pi}{7}}{8sin\frac{\pi}{7}}=\\ =\frac{4sin\frac{2\pi}{7}*cos\frac{2\pi}{7}*cos\frac{4\pi}{7}}{8sin\frac{\pi}{7}}=\frac{2sin\frac{4\pi}{7}*cos\frac{4\pi}{7}}{8sin\frac{\pi}{7}}=\frac{sin\frac{8\pi}{7}}{8sin\frac{\pi}{7}}=-\frac{sin\frac{\pi}{7}}{8sin\frac{\pi}{7}}=-\frac{1}{8}$

15 votes Thanks 35

More Questions From This User See All

kseniyatyutrina July 2022 | 0 Ответы

kak najti ravnodejstvuyushuyu silu esli dve sily ravny po 4n i ugol mezhdu ih vekt

kseniyatyutrina July 2022 | 0 Ответы

vladelec videozalov hochet uvelichit vyruchku ot prodazhi vhodnyh biletov chtoby do

kseniyatyutrina July 2022 | 0 Ответы

2 log 2kornej iz 2x po osnovaniyu 2 1 log 2 po osnovaniyu x log x po osnovani

kseniyatyutrina July 2022 | 0 Ответы

motornaya lodka prohodit rasstoyanie mezhdu pristanyami ai v po techeniyu reki za 25 m

kseniyatyutrina July 2022 | 0 Ответы

velosipedist vyehal iz goroda a v gorod v cherez chas posle svoego vyezda motocik

kseniyatyutrina October 2021 | 0 Ответы

esse bogatstvo semi sobstvennost semisvobodnoe ot nalogov

kseniyatyutrina August 2021 | 0 Ответы

log 8 po osnovaniyu 27

рекомендуемые вопросы

rarrrrrrrr August 2022 | 0 Ответы

o chem dolzhny pozabotitsya v pervuyu ochered vzroslye pri organizacionnom vyvoze n

danilarsentev August 2022 | 0 Ответы

est dva stanka na kotoryh vypuskayut odinakovye zapchasti odin proizvodit a zapcha

myachina8 August 2022 | 0 Ответы

najti po grafiku otnoshenie v3v1 v otvetah napisano 9 no nuzhno reshenie

ydpmn7cn6w August 2022 | 0 Ответы

Choose the correct preposition: 1.I am fond (out,of,from) literature. 2.where ar...

millermilena658 August 2022 | 0 Ответы

opredelite kak sozdavalas i kto sozdaval arabskoe gosudarstvo v kracii

MrZooM222 August 2022 | 0 Ответы

ch ajtmanov v rasskaze krasnoe yabloko ispolzuet metod rasskaz v rasskaze opi

timobila47 August 2022 | 0 Ответы

kakovo bylo naznachenie kazhdoj iz chastej vizantijskogo hrama pomogite pozhalujsta

ivanyyaremkiv August 2022 | 0 Ответы

pozhalujsta8b98a56c0152a07b8f4cbcd89aa2f01e 97513

sarvinozwakirjanova August 2022 | 0 Ответы

pomogite pozhalusto pzha519d7eb8246a08ab0df06cc59e9dedb 6631

Helpful Links

Политика конфиденциальности

Правила и условия

Контакты

Helpful Social

Copyright © 2024 SCHOLAR.TIPS - All rights reserved.