- WE WANT TO IDENTIFY THE COORDINATES,
OR ORDERED PAIR, FOR EACH OF THE POINTS PLOTTED
ON THE COORDINATE PLANE.
TO DO THIS, WE NEED TO REMEMBER THAT THE HORIZONTAL AXIS
IS THE X AXIS AND THE VERTICAL AXIS
IS THE Y AXIS.
SO THE COORDINATES FOR EACH POINT WILL CONSIST
OF AN X COORDINATE AND A Y COORDINATE.
AND THEN THESE ARE ALSO CALLED ORDERED PAIRS.
SO IF WE LOOK AT POINT A, TO DETERMINE THE X COORDINATE
WE JUST NEED TO DRAW A SEGMENT STRAIGHT TO THE X AXIS.
HERE THE X COORDINATE WOULD BE +5 AND THEN WE DRAW
A SEGMENT STRAIGHT TO THE Y AXIS TO IDENTIFY THE Y COORDINATE.
SO THE Y COORDINATE IS +6.
SO FOR POINT A, THE X COORDINATE IS +5
AND THE Y COORDINATE IS +6.
AND IT HAS TO BE IN THIS ORDER.
THE X COORDINATE ALWAYS COMES FIRST
AND THE Y COORDINATE ALWAYS COMES SECOND.
SO IF WE LOOK AT POINT B, THE X COORDINATE
WOULD BE -3 AND THE Y COORDINATE WOULD BE +3.
AGAIN, THIS IS THE X AXIS AND THIS IS THE Y AXIS.
SO POINT B HAS COORDINATES -3, +3.
POINT C IS A LITTLE BIT DIFFERENT.
NOTICE HOW IT LIES ON THE X AXIS.
SO WE CAN SEE THE X COORDINATE IS GOING TO BE -6
AND IF WE DREW A SEGMENT STRAIGHT TO THE Y AXIS,
NOTICE HOW IT WOULD INTERSECT THE Y AXIS RIGHT AT ZERO
AND THAT'S BECAUSE THIS POINT DOES NOT MOVE UP OR DOWN
FROM THE X AXIS.
SO THE Y COORDINATE IS ZERO.
NOW, LET'S TAKE A LOOK AT POINT D,
DOWN HERE IN THE THIRD QUADRANT.
IF WE DRAW A SEGMENT STRAIGHT TO THE X AXIS,
NOTICE HOW IT INTERSECTS THE X AXIS AT -7.
IF WE DRAW A SEGMENT STRAIGHT TO THE Y AXIS,
IT INTERSECTS THE Y AXIS AT -6.
SO THE COORDINATES FOR POINT D WOULD BE -7, -6.
AND THEN FOR POINT E, IF WE GO STRAIGHT TO THE X AXIS,
IT INTERSECTS THE X AXIS AT +2
AND IF WE DRAW A SEGMENT STRAIGHT TO THE Y AXIS,
IT INTERSECTS AT -5.
SO THE X COORDINATE IS +2 AND THE Y COORDINATE IS -5.
FOR THE LAST POINT WE HAVE POINT F, WHICH LIES ON Y AXIS.
SO IF WE DREW A SEGMENT STRAIGHT TO THE X AXIS,
NOTICE HOW IT INTERSECTS THE X AXIS RIGHT AT ZERO.
SO THE X COORDINATE IS ZERO
AND THEN WE CAN SEE THE Y COORDINATE WOULD BE +4.
SO NOTICE HOW WHEN THE POINT LIES ON THE Y AXIS,
THE X COORDINATE IS ALWAYS GOING TO BE ZERO
AND WHEN A POINT LIES ON THE X AXIS,
LIKE POINT C, THE Y COORDINATE WILL ALWAYS BE ZERO.
AND THEN ONE THING THAT I DO WANT TO MENTION,
THERE ARE FOUR QUADRANTS IN THE COORDINATE PLANE
FORMED BY THE INTERSECTION OF THE TWO AXES.
THIS IS THE FIRST QUADRANT.
THIS IS THE SECOND QUADRANT,
THIRD QUADRANT,
AND FOURTH QUADRANT.
SO IN THE FIRST QUADRANT BOTH THE X AND Y COORDINATES
ARE POSITIVE.
IN THE SECOND QUADRANT, THE X COORDINATE IS NEGATIVE,
THE Y COORDINATE IS POSITIVE.
THIRD QUADRANT, BOTH COORDINATES ARE NEGATIVE.
AND THE FOURTH QUADRANT, THE X COORDINATE IS POSITIVE
AND THE Y COORDINATE IS NEGATIVE.
SO POINT A IS IN QUADRANT ONE, POINT B IS IN QUADRANT TWO,
POINT D IS IN QUADRANT THREE, POINT E IS IN QUADRANT FOUR,
AND THEN NOTICE THAT POINTS C AND F
LIE ON THE AXES AND THEY ARE NOT CONSIDERED TO BE IN A QUADRANT.
POINT C LIES ON THE X AXIS AND POINT F LIES ON THE Y AXIS.
I HOPE YOU FOUND THIS HELPFUL.