доказать тождество: sin2a+cos2a*ctga=ctga. Created by KiraraK. matematika-ru

доказать тождество: sin2a+cos2a*ctga=ctga...

liuda666 Ctga-cos2actga-sin2a=0
ctga(1-cos2a)-sin2a=0
ctga(1-cos^2a+sin^2a)-sin2a=0
ctga(sin^2a+cos^2a-cos^2a+sin^2a)-sin2a=0
ctga*2sin^2a-sin2a=0
(cosa/sina)*2sin^2a-sin2a=0
2sinacosa-2sinacosa=0
0=0

3 votes Thanks 3

lexusenok 2sinacosa+(cos^2(a)-sin^2(a))*(cosa/sina)=2sinacosa+(1-2sin^2(a))*(cosa/sina)=2sinacosa+(cosa/sina)-2sinacosa=cosa/sina=ctga

3 votes Thanks 6

Answers & Comments

CaC2-C2H2-CH3COH-CH3COOH-CH3COOC3H7-C3H7OH-C3H7OK | CO2...

v odnomernom massive sostoyashem iz n veshestvennyh elementov vychislit 1 nomer

esli dve razlichnye ploskosti imeyut obshuyu tochku to oni po prohodyashej

chto lezhit v osnovanii pravilnoj treugolnoj piramidy 1 ravnobedrennyj treugol

uravneniya reakcii vzaimodejstviya uksusnoj kisloty v molekulyarnom ionnom i sokra

sostavte strukturnuyu formulu sleduyushih veshestv 44 dimetilpentin 2 2 metigeksad

napishite strukturnye formuly sleduyushih aromaticheskih uglevodorodov 1 1 butil 4

osushestvite prevrashenie po sheme i nazovite veshestva cac2 c2h2 c2h4 c2h4 c2h6 c

osushestvite prevrashenie po predlozhennoj sheme napishite uravneniya reakcii rasst

12 balov zapishite v strukturnom vide uravneniya reakcij gidroliza sleduyushih efir

рекомендуемые вопросы

Helpful Links

Helpful Social