Question

In reperul cartezian xoy se dau punctele A (2, 3) B ( -2, 4) C (4, 1-n). Determinati ecuatia dreptei AB

Answer 1

formula ecuatiei unei drepte  :   y-yB        x-xB      
                                                  -------  =   ------   
                                                  yA-yB      xA-xB
stim ca coordonatele au forma de A(x.y) si B(x.y) vom inlocui
                       
                              y-4     x+2
                              ----- = -----    ⇒ 4(y-4)= -1(x+2) ⇒ 4y-16= -x-2 ⇒ 4y+x-16+2 =0 ⇒ 
                              3-4     2+2

                 x+4y-14  → aceasta este ecuatia dreptei