3...

July 2022 1 7 Report

tg a/2=? если 180<a<270 и tga=4/3

Answers & Comments

Luluput

Verified answer

$tg \alpha = \frac{4}{3}$ $180к\ \textless \ \alpha \ \textless \ 270к$
$tg \frac{ \alpha }{2} -$ ?

$tg \alpha = \frac{2tg \frac{ \alpha }{2} }{1-tg^2 \frac{ \alpha }{2} },$ $\frac{ \alpha }{2} \neq \frac{ \pi }{2} + \pi n,$ $n$ ∈ $Z$ $\frac{ \alpha }{2} \neq \frac{ \pi }{4} + \frac{ \pi }{2} n,$ $n$ ∈ $Z$
$\frac{2tg \frac{ \alpha }{2} }{1-tg^2 \frac{ \alpha }{2} }= \frac{4}{3}$
${6tg \frac{ \alpha }{2} }=4({1-tg^2 \frac{ \alpha }{2} })$
${6tg \frac{ \alpha }{2} }=4-4tg^2 \frac{ \alpha }{2}$
$-4tg^2 \frac{ \alpha }{2} -6tg \frac{ \alpha }{2} +4=0$
$2tg^2 \frac{ \alpha }{2} +3tg \frac{ \alpha }{2} -2=0$
Замена: $tg \frac{ \alpha }{2} =a$
$2a^2 +3 a -2=0$
$D=3^2-4*2*(-2)=25$
$a_1= \frac{-3+5}{4} =0.5$
$a_2= \frac{-3-5}{4} =-2$

$tg \frac{ \alpha }{2} =0.5$ или $tg \frac{ \alpha }{2} =-2$
$180к \ \textless \ \alpha \ \textless \ 270к$
$90к\ \textless \ \frac{ \alpha }{2} \ \textless \ 135к$ - $II$ четверть

Ответ: $tg \frac{ \alpha }{2} =-2$

3 votes Thanks 5

Answers & Comments

Verified answer

kakoj obem kisloroda potrebuetsya dlya polucheniya 10mol vody

napishite reakcii fecol

programmirovanie na pascal abc 1putem kopirovaniya i skleivaniya poluchit iz slov

sintaksicheskij razbor dannogo predlozheniya ya eshe ne vstrechal kota kotorogo by z

polnyj sintaksicheskij razbor predlozheniya vzoshel mesyac ego siyanie prichudlivo pes

tex]...

na risunke ao6sm ac15sm ob9sm bd5sm ab12sm najti cd

3...

vychislite massu digidrofosfata kalciya kotoryj mozhno poluchit dejstviem fosforn

sozdat odnomernyj massiv a iz 10 celyh chisel po formule pervyj chlen raven 5

рекомендуемые вопросы

Helpful Links

Helpful Social