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.
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.
Last edited by avada on Sat Sep 08, 2012 12:23 pm, edited 1 time in total.
