mai intai aflam dreapta AB
AB: [tex] \frac{x-xa}{xb-xa} = \frac{y-ya}{yb-ya} [/tex]
<=> [tex] \frac{x-0}{4-0} = \frac{y+3}{0+3} [/tex]
<=>[tex] \frac{x}{4} = \frac{y+3}{3} [/tex]
<=> 3x = 4y +12 => AB: 3x -4y +12 = 0
acum aflam distanta
[tex]d{(O,AB)} [/tex] = [tex] \frac{|a*x_{0} +b* y_{0} +c| }{ \sqrt{a^{2}+ b^{2} } } [/tex]
= [tex] \frac{|3*0 + (-4)*0 +12|}{ \sqrt{9+16} } [/tex]
= [tex] \frac{12}{5} [/tex]
aceasta este distanta de la punctul O la AB
