SPM Practice 3 (Linear Law) – Question 2


Question 2 (10 marks):
Use a graph to answer this question.
Table shows the values of two variables, x and y, obtained from an experiment. A straight line will be obtained when a graph of y2x against 1x is plotted.


(a) Based on Table, construct a table for the values of 1x and y2x.  
(b) Plot y2x against 1x, using a scale of 2 cm to 0.1 unit on the 1x-axis  and 2cm to 2 units on the y2x-axis.  Hence, draw the line of best fit.

(c) Using the graph in 11(b)
(i) find the value of y when x = 2.7,
(ii) express y in terms of x.

Solution:
(a)


(b)



(c)(i)
When x=2.7, 1x=0.37From graph,y2x=5.2y22.7=5.2y=3.75


(c)(ii)

Form graph, y-intercept, c = –4gradient, m=16(4)0.80=25Y=mX+cy2x=25(1x)4y=254x