Question

A(3,-1) B(1,1) sa se afle dreapta ecuatiei x-my+n=0
m?m?

Answer 1

Dau un raspuns folosind panta : $m_{AB}= \frac{y_{B}-y_{A}}{x_{B}-x_{A}}= \frac{1-(-1)}{1-3}=-1$, scriem ecuatia dreptei ce trece prin punctul B si are panta =-1 : $y-y_{B}=m_{AB}(x-x_{B}),deci,y-1=-1(x-1),$, adica x+y-2=0, de unde m=1, n=-2.