Extreme values of expressions over two ranges
Extreme values of expressions over two ranges
IP 1
7 marks
The real numbers \(x\) and \(y\) satisfy \(-5\le x\le2\) and \(-3\le y\le4\).
- Find the greatest possible value of \(x-y\).[1]
- Find the least possible value of \(xy\).[2]
- Mei says that the greatest possible value of \(xy\) is \(2\times4=8\), because \(2\) and \(4\) are the largest values of \(x\) and \(y\). Explain why Mei is wrong and find the greatest possible value of \(xy\).[2]
- Find the least possible value of \(x^2-y\).[2]
Solution:
Solution locked
680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.
Create a free account to practise similar questions.
Answer:(a) \(5\) (b) \(-20\) (c) \((-5)(-3)=15>8\), so Mei is wrong; greatest value \(15\) (d) \(-4\)
Need help? Join our IP Math tuition programme.
Learn more