2MX vår 1996

Tid: 5 timer

Hjelpemidler: Kalkulator med grafisk vindu. formelark.

Oppgave 1

• $$ 2- 0,85^x=1,8$$

• $$ Cos^2(x)+ Cos(x) -1 =0 $$

• $$lg(x+1) - 1 =0 $$

$$ \textcolor{blue}{lg(x+1) -1 =0 \Rightarrow lg(x+1) =1} $$ $$ \textcolor{blue}{10^{lg(x+1)} = 10^1 \Rightarrow x+1 =10} $$ $$ \textcolor{blue}{x = 9} $$