Specimen 2017 H2 Mathematics Paper 1 Question 2

Graphs and Transformations

Answers

y=12(x+2)3+1.{y=\frac{1}{2} (x+2)^3 + 1.}
x=7.722.{x=7.722.}

Full solutions

(a)

y=x3 y = x^3
Replacing x{x} with x+2,{x+2,} to translate 2{2} units in the negative x-axis,{x\textrm{-axis},}
y=(x+2)3y=(x+2)^3
Stretch of factor 12{\frac{1}{2}} parallel to the y-axis,{y\textrm{-axis},}
y=12(x+2)3y=\frac{1}{2} (x+2)^3
Translation of 1{1} unit in the positive y-direction,{y\textrm{-direction},}
y=12(x+2)3+1  y=\frac{1}{2} (x+2)^3 + 1 \; \blacksquare

(b)

Solving with a GC, at the point where the two curves intersect, x=7.7218 (4 d.p.)  {x=7.7218 \textrm{ (4 d.p.)} \; \blacksquare}
x{x}
y{y}
(0,0){(0,0)}
(0,5){(0, 5)}
(7.722,460.4){(7.722, 460.4)}
y=f(x){y=f(x)}
y=x3{y=x^3}
x-intercept{x\textrm{-intercept}} of y=f(x):{y=f(x):} (232,0){(\sqrt[3]{-2}-2,0)}