If dy > 0 and yz < 0, which of the following must be negative:	Choose the correct choice from the following answers:
A) dyz B) dy(z^2) C) d(y^2)z D) x(y^2)(z^2) E) (x^2)(y^2)(z^2)
dy &gt; 0 means that dy is positive.   yz &lt; 0 means that yz is negative.   d(y^2)z = (dy)(yz) = positive*negative = negative. Thus option d(y^2)z is always negative.
<result>C</result>
If dy > 0 and yz < 0, which of the following must be negative: