SPM practice 3 (Linear Law) - Question 2

Question 2

The table below shows the corresponding values of two variables, x and y, that are related by the equation y=5h x 2 + k h x , where h and k are constants.

(a) Using a scale of 2 cm to 1 unit on the x - axis and 2 cm to 0.2 units on the y x  – axis, plot the graph of y x   against x .  Hence, draw the line of best fit.
(b) Use your graph in (a) to find the values of
(i) h,
(ii) k,
(iii) y when x = 6.

Solution

Step 1 : Construct a table consisting X and Y.


Step 2 : Plot a graph of Y against X, using the scale given and draw a line of best fit

Steps to draw line of best fit - Click here
Step 3 : Calculate the gradient, m, and the Y-intercept, c, from the graph



Step 4 : Rewrite the original equation given and reduce it to linear form

Step 5 : Compare with the values of m and c obtained, find the values of the unknown required


(b) (iii) find the value of y when x=6.