Using paper and pencil, find the QR factorizations of the matrices in Exercises 15 through 28. (Compare with Exercises 1 through 14.)

Natural or Counting Numbers : {1,2,3,4,5,…} "0" is NOT one of them a. Natural numbers start w/ "1" and continue on to infinity Whole Numbers: {0,1,2,3,4,5...} a. Whole numbers start with "0" and continue on to infinity b. NO fractions Integers: { …-3,-2,-1,0,1,2,3...} a. These are whole numbers (0,1,2,3,…) with negative #s included Rational Numbers: any # which can be written in form of a/b (fraction) a. ½ b. - ½ c. .33 = 1/3 d. .66 = 1/6 Prime Numbers: #s that can ONLY be divided by "1" and itself a. CANNOT be an even number (2, 4, 6, 8...) b. 1, 7, 11, 13... Composite #: has more than "1" as a factor a. 4 = 2, 2 b. 6 = 2, 3 c. 9 = 3, 3 Commutative Property: think of the word "commute" - same distance to and