Question 57480
Solve f(x)=x^2-2x-3>0.
Consider the equality:
f(x)=x^2-2x-3=0
Factor to get:
(x-3)(x+1)=0
x=3 or x=-1
Draw a number line.
Put -1 and 3 iin their appropriate positions.
The break the line into three intervals:
I.: (-inf,-1)
II: (-1,3)
III: (3,inf)
Check a point in each interval to determine where the 
solutions of the inequal lie:
I: say x=-10, then f(-10)>0 so I is part of the solution set.
II: say x=0, then f(0)=-3<0 so II is not part of the soution.
III: say x=10, then f(10)>0 so III is part of the solution set.
Conclusion: The solution of the inequality is (-inf,-1) or (3,inf).
Cheers,
Stan H.