[size=100]Sometimes you see a vector [math]\text{\vec{a}}[/math] written as [math]\text{\vec{AB}}[/math].[br]This means the vector goes from A to B.[br]Calculation: [math]\text{\vec{AB}}[/math] = B - A  = [math]\binom{b_x}{b_y}[/math]-[math]\binom{a_x}{a_y}[/math][/size]=[math]\binom{b_x-a_x}{b_y-a_y}[/math][br][size=85][size=100][math]\binom{a_x}{a_y}[/math][/size][/size] are the koordinates of the point A.[br][br]Excersice: Move the slider and look at the vector and the graphics. [br] If you think you know the answer to the vector, you can check it anytime.