Чему равен cos a, если sin a/2=1/4. Created by Alenka2409. matematika-ru

4...

Alenka2409 @Alenka2409

July 2022 2 4 Report

Чему равен cos a, если sin a/2=1/4

inblu

Verified answer

$cosa=cos^2 \frac{a}{2}-sin^2 \frac{a}{2}=1-2sin^{2} \frac{a}{2}=1-2( \frac{1}{4})^2=1-2* \frac{1}{16}= \frac{7}{8}$

1 votes Thanks 3

julyap $cosa=cos^{2} \frac{a}{2} -sin ^{2} \frac{a}{2} \\ cos \frac{a}{2} = \sqrt{1- \frac{1}{16} } = \frac{ \sqrt{15} }{4} \\ cosa= \frac{15}{16} - \frac{1}{16} = \frac{15-1}{16} = \frac{14}{16} = \frac{7}{8} =0.875$

0 votes Thanks 1

Answers & Comments

Verified answer

chisla ot 1 do 20 razbili na pary i chisla v kazhdoj pare slozhili kakoe naibolshee

h5menshe ili ravno 4h

8?...

h8 menshe ili ravno 2h8bbc2493beaa36c747c246f6387da67b 6153

2 esli sin x06 0

pismo lermontova k budushemu pokoleniyu

рекомендуемые вопросы

Helpful Links

Helpful Social