Question 562197
Find all values of x in the interval [0, 2π] that satisfy the inequality. 
&#8722;9 < 9 tan(x) < 9
&#8722;1 <  tan(x) < 1
tan(x) > -1
tan(x) < 1
..
Intervals in which x-values (radians) satisfy the inequality:
for tan(x) < 1
[0, &#960;/4) and [&#960;, 5&#960;/4) (quadrants I and III where tan>0)
.. 
for tan(x) > -1
(3&#960;/4,&#960;] and (7&#960;/4,2&#960;]  (quadrants II and IV where tan<0)