Data Sufficiency

a does not equal zero, is (1/a)>(a/b^4+3)?
1. a^2=b^2
2.a^2=b^4


I understand that we cross multiply and need to figure out the sign of a.
1. Shows us that a must be positive therefore is sufficient.
2. I dont understand how this doesnt show us that a is positive. we know that b^4 must be positive right? It is an even integer exponent just like b^2 was....

Im confused why we dont know A is positive in the second statement.

avada wrote:a=/=0, is (1/a)>(a/b^4=3)?

I'm not sure what this means.

Hi,

It seems the question is (1/a) > [{a/(b^4)}+3]

Stmt 1: (1/a)> [{1/(a^3)}+3]
If -1 > a > 0 The reverse of the above inequality will be true.
If -1 < a < 0 The direct inequality will be true.
insufficient.
Stmt 2: (1/a)> (1/a)+3
sufficient.

Ans: B

Regards,
Kapil