Q79 of 90 Page 372

Consider this input/output table.


(a) Graph the values from the table by taking input along horizontal axis from 0 to 8 and Output along vertical axis from 0 to 24.


(b) Use your graph to predict the outputs for inputs of 3 and 8.

(a) Let as plot the graph as per the given table. It is shown as below



This graph follows y = 3x-1 pattern.


(b) The graph follows y = 3x-1 pattern.


If x = 3 then y = (3 ×3)-1 = 5


If x = 8 then y = (3 ×8)-1 = 23



More from this chapter

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77

This graph shows the per cent of students who dropped out of school after completing High School. The point labelled A shows that, in 1996, about 4.7% of students dropped out.


A) In which year was the dropout the rate highest? In which year was it the lowest?


B) When did the per cent of students who dropped out of high school first fall below 5%?


C) About what per cent of students dropped out of high school in 2007? About what per cent of students stayed in high school in 2008?

78

Observe the toothpick pattern given below:



(a) Imagine that this pattern continues. Complete the table to show the number of toothpicks in the first six terms.



(b)Make a graph by taking the pattern numbers on the horizontal axis and the number of toothpicks on the vertical axis. Make the horizontal axis from 0 to 10 and the vertical axis from 0 to 30.


(c) Use your graph to predict the number of toothpicks in patterns 7 and 8. Check your answers by actually drawing them.


(d) Would it make sense to join the points on this graph? Explain.

80

This graph shows a map of an island just off the coast of a continent. The point labelled B represents a major city on the coast. The distance between grid lines represents 1 km.


Point A represents a resort that is located 5 km East and 3 km North of point B. The values 5 and 3 are the coordinates of point


A. The coordinates can be given as the ordered pair (5, 3), where 5 is the horizontal coordinate and 3 is the vertical coordinate.


(i) On a copy of the map, mark the point that is 3 km East and 5 km North of Point B and label it S. Is point S in the water or on the island? Is point S in the same place as Point A?


(ii) Mark the point that is 7 km east and 5 km north of point B and label it C. Then mark the point that is 5 km east and 7 km north of point B and label it D. Are points C and D in the same place? Give the coordinates of Points C and D.


(iii) Which point is in the water, (2, 7) or (7, 2)? Mark the point which is in water on your map and label it E.


(iv) Give the coordinates of two points on the island that are exactly 2 km from Point A.


(v) Give the coordinates of the point that is halfway between Points L and P.


(vi) List three points on the island with their x-coordinates greater than 8.


(vii) List three points on the island with a y-coordinate less than 4.

81

As part of his science project, Prithvi was supposed to record the temperature every hour one Saturday from 6 am to midnight. At noon, he was taking lunch and forgot again. He recorded the data so collected on a graph sheet as shown below.


A) Why does it make sense to connect the points in this situation?


B) Describe the overall trend, or pattern, in the way the temperature changes over the time period shown on the graph.


C) Estimate the temperature at noon and 8 pm.