Fill in the blanks:
(i) The horizontal line X'OX in a coordinate plane is called ..... .
(ii) The point of intersection of x-axis and y-axis is called ..... .
(iii) In a cartesian plane x-coordinate of a point is also called ..... .
(iv) The two axes divide the plane into four parts called ..... .
(v) The y-coordinate of a point is ..... , if it is measured below the origin.
(vi) Area of circle depends on the radius of circle, then radius of circle is called ..... variable.
Answer
(i) The horizontal line X'OX in a coordinate plane is called x-axis.
(ii) The point of intersection of x-axis and y-axis is called origin.
(iii) In a cartesian plane x-coordinate of a point is also called abscissa.
(iv) The two axes divide the plane into four parts called quadrants.
(v) The y-coordinate of a point is negative, if it is measured below the origin.
(vi) Area of circle depends on the radius of circle, then radius of circle is called independent variable.
State whether the following statements are true (T) or false (F):
(i) x-axis and y-axis taken together are called coordinate axes.
(ii) The y-coordinate of a point is called abscissa.
(iii) Point (0, 0) lies on both the coordinate axes.
(iv) Point (0, 2) lies on x-axis.
(v) Graph joining the points (2, 3), (2, 5) and (2, 7) is a line parallel to y-axis.
(vi) The point (-2, 3) lies in third quadrant.
Answer
(i) The horizontal line X'OX and the vertical line Y'OY, taken together, are called the coordinate axes.
Hence, the given statement is True.
(ii) The y-coordinate of a point is called its ordinate, whereas the x-coordinate of a point is called its abscissa.
Hence, the given statement is False.
(iii) The point (0, 0) is the origin, which is the point of intersection of the two axes.
So, it lies on the x-axis as well as on the y-axis.
Hence, the given statement is True.
(iv) The abscissa of the point (0, 2) is zero, so the point lies on the y-axis and not on the x-axis.
Hence, the given statement is False.
(v) The abscissa of each of the points (2, 3), (2, 5) and (2, 7) is 2.
So, each of these points is at a distance of 2 units to the right of the y-axis, and hence the line joining them is parallel to the y-axis.
Hence, the given statement is True.
(vi) In the point (-2, 3), the abscissa is negative and the ordinate is positive.
So, the point (-2, 3) lies in the second quadrant and not in the third quadrant.
Hence, the given statement is False.