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 y 2 x  against  1 x is plotted.


(a) Based on Table, construct a table for the values of 1 x  and  y 2 x .  
( b ) Plot  y 2 x  against  1 x , using a scale of 2 cm to 0.1 unit on the  1 x -axis   and 2cm to 2 units on the  y 2 x -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,  1 x =0.37 From graph, y 2 x =5.2 y 2 2.7 =5.2 y=3.75


(c)(ii)

Form graph, y-intercept, c = –4 gradient, m= 16( 4 ) 0.80 =25 Y=mX+c y 2 x =25( 1 x )4 y= 254x