4MA0 Higher June 2014 Paper 3 Q17
17 Make \(x\) the subject of \(y = \sqrt{\dfrac{2x + 1}{x - 1}}\)
(4)
| Scheme | Marks |
|---|---|
| \(y^2 = \dfrac{2x + 1}{x - 1}\) | M1 |
| \(y^2(x - 1) = 2x + 1\) \(y^2x - y^2 = 2x + 1\) | M1 |
| \(y^2x - 2x = y^2 + 1\) | M1 |
| \(x = \dfrac{y^2 + 1}{y^2 - 2}\) oe | A1 |
| (4 marks) |
Notes
M1: squaring both sides to get a correct equation
M1: removing denominator to get a correct equation
M1: correctly gathering \(x\)s on one side of a correct equation with non \(x\) terms on the other side