Og Pg 151 Problem 4

[lmiller.1102]

the answer to this question is b,however i think its D.
x sq2 y> 0 ,in this case x can be negative and y position and the product can still be greater than 0.
or both can be positive and the product greater than 0.

similarly for the next part x y sq2<0,
here both are negative.

so basically when we dont have a definite value for x, it should be d.
Can you please help .

[tommywallach]

Hey LMiller,

x^2 * y > 0

What this tells you is that y is positive. As you noticed, x could be negative or positive. But we definitively know that y is positive.

x * y^2 < 0

This tells you that x is negative. It has to be, because y^2 is positive no matter what.

So we know that y is positive and x is negative.

Make sense?

-t