Graphs and transformations

Question code: 2A57

Question 0305

(i)

Write y=x2x+7{\displaystyle y = \frac{ - x - 2 }{ x + 7 }} in the form y=A+Bx+7{\displaystyle y = A + \frac{B}{x + 7}} and describe a sequence of transformations which transform the graph of y=x2x+7{\displaystyle y = \frac{ - x - 2 }{ x + 7 }} to the graph of y=1x.{\displaystyle y = \frac{ 1 }{ x }.}
[4]

(ii)

Sketch the graph of y=x2x+7,{\displaystyle y = \frac{ - x - 2 }{ x + 7 },} giving the equations of any asymptotes and the coordinates of any axial intercepts.
[3]
Answer
y=1+5x+7{y = -1 + \frac{ 5 }{ x + 7 }}
Transformation 1: Translate by 1 units in the positive y{y}-axis direction.
Transformation 2: Scale by a factor of 15{\frac{1}{5}} parallel to the y{y}-axis.
Transformation 3: Translate by 7 units in the positive x{x}-axis direction.
Question code: 2A57