Question 1 - Think and Reflect (Page 33) - Visualising Linear Relationships - Chapter 2 Class 9 - Introduction to Linear Polynomials (Ganita Manjari

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Question 1 - Think and Reflect (Page 33) Differentiate between the graphs of the equations y = 3x + 1, and y = –3x + 1. To draw the graph, we join points which lie on the line For y = 3x + 1 Putting x = 0 y = 3 × 0 + 1 y = 0 + 1 y = 1 So, x = 0, y = 1 lie on the line i.e. (0, 1) lies on the line Putting x = 1 y = 3 × 1 + 1 y = 3 + 1 y = 4 So, x = 1, y = 4 lie on the line i.e. (1, 4) lies on the line For y = –3x + 1 Putting x = 0 y = –3 × 0 + 1 y = 0 + 1 y = 1 So, x = 0, y = 1 lie on the line i.e. (0, 1) lies on the line Putting x = 1 y = –3 × 1 + 1 y = –3 + 1 y = –2 So, x = 1, y = –2 lie on the line i.e. (1, –2) lies on the line We plot all the points in the graph and join the points y = 3x + 1 y = –3x + 1 Thus, we observe that for lines y = 3x + 1 and y = –3x + 1 Both have same y-intercept (b = 1) Lines have opposite signs of slope. So, while going from left to right, one line goes up and one line goes down