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

1 Answer
Sep 24, 2017

Answer:

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

Explanation:

# 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]