Question

[Yunie]

I have difficulty doing this question. Please help, thanks. :)

The variables x and y are related in such a way that when y^2 is plotted against x^2y, a straight line is obtained which passes through the points (3,5) and (5,9)


(a) Express x in terms of y

(b) Find the two values of y for which x = 1/2 √5


Thanks.

[VBAhack]

I assume x^2y means (x2)y and not x(2y). For a linear relationship, w = mz + b, where m is the slope and b is the intercept. If you have 2 points you can figure out m and b:

w1 = mz1 + b
w2 = mz2 + b

m = (w2 - w1) / (z2 - z1)
b = w1 - mz1

In this case w = y2 and z = x2y

So, m = (y22 - y12) / ( x22y2 - x12y1)

you should be able to take it from there.