Porisma

A hint to get started

Prove a quadratic is positive before removing it

For real x, prove 2x2−x+22x^2-x+2 is always positive. Solve (3x−1)/(2x2−x+2)≥1/x(3x-1)/(2x^2-x+2)\ge1/x, leaving the answer in exact form.

[2013/NJC/I/2(part)]

CJC · Lecture · Example 5

Mark critical values and decide which are allowed before selecting intervals.

Read the worked solution