2026 HGV P2 Q3

2026 HGV P2 Q3

Secondary 4
8 marks

In the binomial expansion of \(\left(2x+\dfrac{k}{x}\right)^8\), where \(k\) is a positive constant, the coefficient of \(x^2\) is 28.

  1. Show that \(k=\dfrac14\).[4]
  2. Hence, find the term in \(x\) in the expansion of \(\left(6x-\dfrac1x\right)\left(2x+\dfrac{k}{x}\right)^8\).[4]

Solution:

Solution locked

Sign in to view the step-by-step solution

Similar questions are unavailable for this question.
Answer:(a) \(k=\dfrac14\) (shown). (b) \(-\dfrac74x\).

Need help? Join our JC Math tuition classes.

Learn more