How do you solve $1/x<4$ using a sign chart?

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Answer 1 · 2017-09-24T11:51:30

Solution : $x<0 or x >1/4 or (-oo,0) uu(1/4,oo)$

$1/x <4 or 1/x-4 <0 or (1-4x)/x <0$ critical points are

$x=0 , 1-4x=0 or x=1/4$ . Function is undefined at $x=0$

Sign chart :

When $x<0$ sign of $(1-4x)/x$ is $(+/-) = - ; <0$

When $0< x<1/4$ sign of $(1-4x)/x$ is $(+/+) = + ; >0$

When $x >1/4$ sign of $(1-4x)/x$ is $(-/+) = - ; <0$

Solution : $x<0 or x >1/4 or (-oo,0) uu(1/4,oo)$ [Ans]

How do you solve 1/x<41/x<4 using a sign chart?