2020 ACJC P1 Q4

2020 ACJC P1 Q4

8 marks
Prelims
  1. Find the roots of the equation \(b\left| x-a \right|=x-ab\), where \(a\) and \(b\) are constants.[2]
  2. If \(a < b < 0\),
    1. write down a condition for \(b\left| x-a \right|=x-ab\) to have a negative real root.[1]
    2. using the same condition from (a), on the same axes, sketch the graphs of \(y=x-ab\) and \(y=b\left| x-a \right|\),[2]
      Hence solve the inequality
      \(b\left| x-a \right|\ge x-ab\).[1]
      Deduce the set of values of \(x\) for which
      \(-b\left| {{\mathrm{e}}^{x}}+a \right|\le {{\mathrm{e}}^{x}}+ab\).[2]

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs a course plan.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

Answer:(i) x = 0 or 2ab/(1+b); (ii)(a) b < -1; (ii)(b) x ≤ ln(-2ab/(1+b))

Need help? Join our JC Math tuition classes.

Learn more