__Question 4__The table below shows the corresponding values of two variables, x and y, that are related by the equation $y=qx+\frac{p}{qx}$ , where p and q are constants.

One of the values of y is incorrectly recorded.

(a) Using scale of 2 cm to 5 units on the both axis, plot the graph of xy against ${x}^{2}$ . Hence, draw the line of best fit

(b) Use your graph in (a) to answer the following questions:

(i) State the values of y which is incorrectly recorded and determine its actual value.

(ii) Find the value of p and of q.

Solution

**: Construct a table consisting X and Y.**

*Step 1***: Plot a graph of Y against X, using the scale given and draw a line of best fit**

*Step 2*

*Steps to draw line of best fit - Click here***(b) (i) State the values of y which is incorrectly recorded and determine its actual value.**

*Step 3 :*Calculate the gradient, m, and the Y-intercept, c, from the graph

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

*Step 4***: Compare with the values of m and c obtained, find the values of the unknown required**

*Step 5*