What is the equation of a hyperbola with a center at (2, -3), horizontal axis, a distance of 4 units from the center to each vertex, and a distance of 6 units from the center to each focus?
+
What is the number of ways to arrange 5 books on a shelf when 2 specific books must always be next to each other?
+
What is the 5th derivative of f(x) = 2x^4 - 3x^2 + 5x - 7?