What shape is the cross-section? a. Triangle
b. Circle
c. Ellipse
d. Hexagon
e. Square
f. Rectangle
g. Pentagon

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?