__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**

*Step 1**X*and

*Y*.

**: Plot a graph of**

*Step 2**Y*against

*X*, using the scale given and draw a line of best fit

*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**

*Step 5**m*and

*c*obtained, find the values of the unknown required