Question

Fie punctele A (1,2) , B (2,3). Determinați ecuația dreptei AB

Answer 1

$A(1,2),\:B(2,3)\\ ecuatia\:dreptei\:AB\:este:\frac{x-x_B}{x_A-x_B}=\frac{y-y_B}{y_A-y_B}\\ \frac{x-2}{1-2}=\frac{y-3}{2-3}\Leftrightarrow\frac{x-2}{-1}=\frac{y-3}{-1}\Leftrightarrow-(x-2)=-(y-3)\Leftrightarrow x-2=y-3\\ \Leftrightarrow AB:x-y+1=0$