# Help: Case analysis

• October 2nd 2008, 06:16 AM
rednest
Help: Case analysis
Solve the inequality $\frac{1}{x} by Case Analysis.

What is 'Case Analysis' ??
• October 2nd 2008, 07:29 AM
Plato
Consider two cases:
Case I. $x>0$ and then solve.

Case II. $x<0$ annd then sove.
• October 2nd 2008, 10:40 AM
Showcase_22
Have you noticed that on MA132 Foundations Exercises 1 there's a typo in Section A? 1 ii) doesn't make sense!

Anyway, plato was right with what he posted.

Remember to flip the inequality sign around when you take s as a negative.

$\frac{1}{x}

If x is negative then multiply through by x and flip the signs around:

$1>x^2>x$

Then solve each separate equation:

$1>x^2$ and $x^2>x$.

When x is positive, just solve $1 by splitting it into two separate inequalities like above.

Hope it helps!