Page 70 - Mathematics Class - XI

Viva-Voce

1. What is meant by slope of the line?
Ans. The trigonometrical tangent of the angle that a non-vertical line makes with the positive direction of the
x-axis in anticlockwise direction is called the slope or gradient of the line.
2. What is the slope of a non-vertical line passing through the points (x , y ) and (x , y )?
1 1 2 2
y − y
Ans. The slope m of a non-vertical line passing through the points (x , y ) and (x , y ) is given by m = x − x 1
2
1
1
2
2
3. What is the equation of the line which passes through the points (x , y ) and having slope m? 2 1
1 1
Ans. y – y = m(x – x )
1 1
4. What is the general equation of a first degree in two variables?
Ans. Any equation of the form Ax + By + C = 0, where A and B are non zero simultaneously, is called general
equation of a line.
5. Is the graph of equation Ax + By + C = 0 always a straight line?
Ans. Yes, the graph of equation Ax + By + C = 0 is always a straight line.
6. What is the equation of line cutting intercepts a and b on two coordinates axes x and y respectively?

x y
Ans. + = 1
a b

MCQs

1. Slope of that line, which makes an angle of 30° with the y-axis, will be

a) − 3 b) 3 c) ± 1 d) ± 3
3
2. Points (k, 2k), (2k, 3k) and (3, 1) are collinear then the value of k will be

a) –2 b) − 1 c) 1 d) 3
2 2 2
3. If the point L is at equidistance from the points A (1, 3), B (–3, 5), C (5, –1) then the value of LA will be

a) 5 b) 55 c) 25 d) 510
4. The length of the perpendicular drawn from point (2, –1) to the line 2x + 5y = 7

a) 8 b) 7 c) 8 d) None of these
29 28 30
5. Find the value of the distance between lines 5x + 3y = 7 and 15x + 9y + 14 = 0

a) 35 b) 1 c) 35 d) 35
34 334 334 234
6. The image point of the point (4, –13) with respect to the 5x + y = –6 will be
a) (–1, –14) b) (3, 4) c) (0, 0) d) (1, 2)

Answers: 1. d) ± 3 2. a) –2 3. d) 510 4. a) 8 5. c) 35 6. a) (–1, –14)
29 334
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