Josepha – GufoSaggio

Come valuta $cos [2 {sin}^{- 1} (\frac{5}{13})]$ $cos [2sin ^ -1 (5/13)]$ ?

Dicembre 20, 2019

Come valuta $cos [2 {sin}^{- 1} (\frac{5}{13})]$ $cos [2sin ^ -1 (5/13)]$ ? Risposta: La soluzione è $\frac{119}{169}$ $119/169$ o 0.7041 Spiegazione: Assumere ${sin}^{- 1} (\frac{5}{13}) = x$ $sin^(-1)(5/13)=x$ _(1) $\Rightarrow sin x = \frac{5}{13}$ $=>sinx=5/13$ _____ (2) Quindi $cos (2 {sin}^{- 1} (\frac{5}{13}))$ $cos(2sin^(-1)(5/13))$ = $cos 2 x$ $cos2x$ [da equazione di freom (1)] $= 1 - 2 {sin}^{2} x$ $=1-2sin^2x$ $= 1 - 2 {(\frac{5}{13})}^{2}$ $=1-2(5/13)^2$ $= \frac{119}{169}$ $=119/169$ quale è la soluzione richiesta.

How can I memorize the polyatomic ions? Is there an acronym?

Dicembre 20, 2019

di Josepha

How can I memorize the polyatomic ions? Is there an acronym? There is no acronym. Mostly you learn them by using them. You could make flashcards using note cards, starting with the most familiar ones, then adding more note cards with more ioni poliatomici. You could ask your teacher which ones you are expected to … Leggi tutto