Exercise 1

(i) Calculate the ratio in which the line segment joining (3, 4) and( – 2, 1) is divided by the y-axis. (ii) In what ratio does the line x – y – 2 = 0 divide the line segment joining the points (3, – 1) and (8, 9)? Also, find the coordinates of the point of division.

Solution: (i) Let m:n be the ratio in which the line segment joining (3,4) and (-2,1) is divided by the Y axis. Since the line meets Y axis, its x co-ordinate is zero. Here x1 = 3, y1 = 4 x2 = -2,...

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(i) In what ratio does the point (5, 4) divide the line segment joining the points (2, 1) and (7 ,6) ? (ii) In what ratio does the point ( – 4, b) divide the line segment joining the points P (2, – 2), Q ( – 14, 6) ? Hence find the value of b.

Solution: (i) Let the ratio that the point (5,4) divide the line segment joining the points (2,1) and (7,6) be m:n, Here x1 = 2 , y1 = 1 , x2 = 7, y2 = 6, x = 5, y = 4 By section formula, x =...

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Use graph paper for this question. Take 1 cm = 1 unit on both axes. Plot the points A(3, 0) and B(0, 4).(iii) Assign the special name to the quadrilateral ABA1B1. (iv) If C is the midpoint is AB. Write down the co-ordinates of the point C1, the reflection of C in the origin.

(iii) The quadrilateral ABA1B1 will be a rhombus. (iv) Let C be midpoint of AB. Co-ordinate of C = ((3+0)/2 , (0+4)/2) = (3/2, 2) [Midpoint formula] In a point reflection in the origin, the image of...

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Use graph paper for this question. Take 1 cm = 1 unit on both axes. Plot the points A(3, 0) and B(0, 4). (i) Write down the co-ordinates of A1, the reflection of A in the y-axis. (ii) Write down the co-ordinates of B1, the reflection of B in the x-axis.

(i) Co-ordinates of point A are (3,0). When you reflect a point across the Y-axis, the y-coordinate remains the same, but the x-coordinate is transformed into its opposite (its sign is changed)...

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Point P (3, – 5) is reflected to P’ in the x- axis. Also P on reflection in the y-axis is mapped as P”. (iii) Find the middle point of the line segment P’ P”. (iv) On which co-ordinate axis does the middle point of the line segment P P” lie ?

(iii) Co-ordinates of P’ = (3,5) Co-ordinates of P’’ = (-3,-5) Here x1 = 3, y1 = 5 , x2 = -3, y2 = -5 Let Q(x,y) be the midpoint of P’P’’ By midpoint formula, x = (x1+x2)/2 y = (y1+y2)/2 x =...

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(i) The line segment joining the points A (3, 2) and B (5, 1) is divided at the point P in the ratio 1 : 2 and it lies on the line 3x – 18y + k = 0. Find the value of k. (ii) A point P divides the line segment joining the points A (3, – 5) and B ( – 4, 8) such that AP/PB = k/1 If P lies on the line x + y = 0, then find the value of k.

Solution: (i) Let the co-ordinates of P(x, y) divides AB in the ratio m:n. A(3,2) and B(5,1) are the given points. Given m:n = 1:2 x1 = 3 , y1 = 2 , x2 = 5 , y2 = 1 , m = 1 and n = 2 By Section...

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(i) Find the co-ordinates of the points of trisection of the line segment joining the point (3, – 3) and (6, 9). (ii) The line segment joining the points (3, – 4) and (1, 2) is trisected at the points P and Q. If the coordinates of P and Q are (p, – 2) and (5/3, q) respectively, find the values of p and q.

Let P and Q be the points of trisection of AB i.e., AP = PQ = QB Given A(3,-3) and B(6,9) x1 = 3, y1 = -3, x2 = 6, y2 = 9 P(x, y) divides AB internally in the ratio 1 : 2. m:n = 1:2 By applying the...

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