Big Ideas Math Integrated I, 2016
BI
Big Ideas Math Integrated I, 2016 View details
Chapter Test
Continue to next subchapter

Exercise 11 Page 491

If n is an even integer, how can we express the odd integer that comes right after?

See solution

Practice makes perfect
Inductive reasoning uses specific examples to find patterns in order to form a conjecture. Let's try and add three odd numbers a few times and see what happens: First trial:& 1+1+3 =5 Second trial:& 3+5+7 =15 Third trial:& 5+7+9 =21 Fourth trial:& 7+9+11=27What do all of these numbers have in common? Well, for one, they are all odd. 5/2=2.5, 15/2=7.5, 21/2=10.5, 33/2=16.5 Let's use deductive reasoning to prove this conjecture. If we let x, y, and z represent arbitrary numbers, then (2x+1) is an arbitrary odd number, as are (2y+1) and (2z+1). If we add these, we can prove that the sum of three odd integers is odd.
(2x+1)+(2y+1)+(2z+1)
2x+2y+2z+1+1+1
2x+2y+2z+2+1
2(x+y+z+1)+1
Since 2(x+y+z+1) has a factor of 2, it is an even number. Any even number plus 1 is an odd number. VOILA!