What is the nature of roots of a quadratic equation with a discriminant of -4? a. nonreal
b. real, rational, and equal
c. real, rational, and unequal
d. real, irrational, and unequal

Aresearch company wants to test the claim that a new multivitamin to improve short term memory. state the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

Determine whether the following statements are true and give an explanation or counterexample. bold a. when using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. bold b. if a region is revolved about the y-axis, then the shell method must be used. bold c. if a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y.