Question

exercițiul 6
dau coroana ​

Answer 1

<1=3^(n+2)-3^n

<2=3^(n+2)+3^(n+1)

d ll g AB secantă

<1+<2=180⁰

3^(n+2)-3^n+3^(n+2)+3^(n+1)=180⁰

9×3^n-3^n+9×3^n+3×3^n=180⁰

20×3^n=180⁰

3^n=9

n=2

<1=3^(n+2)-3^n=3⁴-3²=3²(3²-1)=72⁰

3^(n+2)+3^(n+1)=3⁴+3³=3³(3+1)=27×4=108⁰