MATH 201 Midterm: MATH 201 Exam 7
Document Summary
To succeed you will need to know the de nitions, basic theorems, and be able to methodically take apart a problem and provide a proof of statements. Given a quadratic ax2 + bx + c = 0 we can solve. The absolute value function |x|, drops the sign of x, but more importantly gives a measurement of dis- tance. If x and y are real numbers, |x + y| 6 |x| + |y|. Two important means are the arithmetic mean ((x + y)/2) and the geometric mean ( xy). 2 (cid:1)2 numbers, then 2xy 6 x2 + y2 and xy 6 (cid:0) x+y y are also nonnegative then xy 6 x+y. A set a is a collection of objects, we use x a to indicate that x is in the set a. We can describe a set by listing elements, i. e. , a = {x, y, z} or giving a description, i. e. , a = {n : n is even}.
