Why do this problem?
This is a non standard example of a quadratic inequality.
Possible approach
Encourage the learners to substitute
and to rearrange the expression into a quadratic
inequality involving
, then to find the factors of the quadratic expression.
It may then be helpful for the class to work together to solve the inequality.
A fruitful class discussion, where the learners are able to volunteer suggestions
for the steps in the working, is more likely to ensue if they have at least
started solving the problem for themselves and have worked through the earlier
steps.
Key questions
When you have solved a quadratic equation can you write down the
factors of the quadratic expression?
If you know that the product of two factors is negative what can
you say about the factors?
If you have solved the inequality for
how do you find the inequality for
?