Lecture-8

Straight Lines Lecture 8
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Straight Lines Lecture 8
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00:00:35 NCERT Exercise 10.2 Question 14

Find equation of the line through the point (0, 2) making an angle 2π/3 with the positive x-axis. Also, find the equation of line parallel to it and crossing the y-axis at a distance of 2 units below the origin.

00:05:35 NCERT Exercise 10.2 Question 15

The perpendicular from the origin to a line meets it at the point (–2, 9), find the equation of the line.

00:11:05 NCERT Exercise 10.2 Question 16

The length L (in centimetre) of a copper rod is a linear function of its Celsius temperature C. In an experiment, if L = 124.942 when C = 20 and L= 125.134 when C = 110, express L in terms of C.

00:18:55 NCERT Exercise 10.2 Question 17

The owner of a milk store finds that, he can sell 980 litres of milk each week at Rs 14/litre and 1220 litres of milk each week at Rs 16/litre. Assuming a linear relationship between selling price and demand, how many litres could he sell weekly at Rs 17/litre?

00:22:55 NCERT Exercise 10.2 Question 18

P (a, b) is the mid-point of a line segment between axes. Show that equation of the line is x/a + y/b = 2.

00:27:35 NCERT Exercise 10.2 Question 19

Point R (h, k) divides a line segment between the axes in the ratio 1: 2. Find equation of the line.

00:36:45 NCERT Exercise 10.2 Question 20

By using the concept of equation of a line, prove that the three points (3, 0), (– 2, – 2) and (8, 2) are collinear.