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Coordinate geometry example 1

Question: If point A(m, 3) lies on the y-axis, then point B(m + 2, m- 3) lies on which quadrant?

Solution:

Look the coordinate plane, in quadrant I, x is positive and y is positive. In quadrant II, x is negative and y is positive. In quadrant III, x is negative and y is negative. In quadrant IV, x is positive and y is negative.

Because the coordinate of the point A is (m, 3), in which m is unknown. Because we are given that the point A lies on y-axis. Because all points lie on y-axis satisfy the equation x = 0. So, m = 0 (because the point A lies on y-axis, so, m must be zero.)

So, point B (m + 2, m - 3) = B (2, -3). Since for point B, its x coordinate is 2 and y coordinate is -3, so, the point B lies on quadratic IV.