Question

for which values of the following intervals of x is x2>1/x2?

Answer 1

Step-by-step explanation:

1. xbelongs to [1, infinity)

Answer 2

ANSWER

f(x)=2x

2

−log∣x∣

={

2x

2

−logx

2x

2

−log(−x)

x>0

x<0

⇒f

′

(x)=4x−

x

1

,∀x



=0

For f(x) to be increasing

f

′

(x)>0⇒4x−

x

1

>0

⇒

x

4x

2

−1

>0

⇒

x

(2x−1)(2x+1)

>0

⇒x(2x−1)(2x+1)>0

⇒xϵ(−

2

1

,0)∪(

2

1

,∞)