What is the derivative of f(x) = 7x^3 - 5x^2 + 2x - 1?
+
Question: What is the vertex of the quadratic function f(x) = -2x^2 + 5x + 3?
+
What is the median of a set of numbers if the sum of the first three numbers is 15, the sum of the last three numbers is 25, and there are seven numbers in total?