Example1
http://www.youtube.com/watch?v=1pSD8cYyqUo
Example2
http://www.youtube.com/watch?v=TeE-ypKj8ZI&feature=relmfu
Bonus Video: Me and my roommates singing RM Dream (original song with lyrics by my roommate):
http://www.youtube.com/watch?v=nDm74LdP54w
Pete's Math 110
Here are some helpful videos and other items to help with your study of College Algebra. I do not necessarily own or author said videos. Enjoy!
Tuesday, April 5, 2011
Thursday, March 31, 2011
How to write repeating decimals as single fractions.
HOW TO WRITE REPEATING DECIMALS AS A SINGLE FRACTION
By Peter Barrow
Let’s write 1.8989898989… (a repeating decimal) as a single fraction. Before we do that, let’s observe a few things about fractions and repeating decimals. You’ll want a calculator.
Enter 1/9 on your calculator. You get 0.99999999…
Now enter 3/9. You get 0.33333333….
What do you think you’ll get when you type in 7/9? You’re right: 0.7777777777…
Now try 83/99. You should get 0.838383838383…
Hopefully you’re starting to see a pattern. If you were to enter 237/999 you’d get 0.237237237237…
So, back to 1.89898989… Let’s think of it not as 1.8989898989… but rather as 1+0.8989898989… because from our experiment above, we know we can write 0.89898989… as 89/99. So 1+0.8989898989…=1+(89/99). Now we’re just adding fractions, which we can do in our sleep. We need like denominators:
1+(89/99)=(99/99)+(89/99)=(99+89)/99=188/99. Type it in on your calculator if you don’t believe me.
This provides a much simpler way of converting repeating decimals into fractions.
Let’s try some other examples:
10.1234123412341234…=10+(1234/9999)=(99990/9999)+(1234/9999)=(1234+99990)/(9999)=(101224/9999)
5.77777777777… = 5+(7/9)=(45/9)+(7/9)=(45+7)/9=52/9.
3.34343434343434… = 3+(34/99)=(297/99)+(34/99)=(331/99)
Now you try some on your own. I won’t include the answer, because to check your answer you can just type in the fraction you get on a calculator and see if you’re right.
7.55555555…..
8.656565656565….
1.369369369369….
By Peter Barrow
Let’s write 1.8989898989… (a repeating decimal) as a single fraction. Before we do that, let’s observe a few things about fractions and repeating decimals. You’ll want a calculator.
Enter 1/9 on your calculator. You get 0.99999999…
Now enter 3/9. You get 0.33333333….
What do you think you’ll get when you type in 7/9? You’re right: 0.7777777777…
Now try 83/99. You should get 0.838383838383…
Hopefully you’re starting to see a pattern. If you were to enter 237/999 you’d get 0.237237237237…
So, back to 1.89898989… Let’s think of it not as 1.8989898989… but rather as 1+0.8989898989… because from our experiment above, we know we can write 0.89898989… as 89/99. So 1+0.8989898989…=1+(89/99). Now we’re just adding fractions, which we can do in our sleep. We need like denominators:
1+(89/99)=(99/99)+(89/99)=(99+89)/99=188/99. Type it in on your calculator if you don’t believe me.
This provides a much simpler way of converting repeating decimals into fractions.
Let’s try some other examples:
10.1234123412341234…=10+(1234/9999)=(99990/9999)+(1234/9999)=(1234+99990)/(9999)=(101224/9999)
5.77777777777… = 5+(7/9)=(45/9)+(7/9)=(45+7)/9=52/9.
3.34343434343434… = 3+(34/99)=(297/99)+(34/99)=(331/99)
Now you try some on your own. I won’t include the answer, because to check your answer you can just type in the fraction you get on a calculator and see if you’re right.
7.55555555…..
8.656565656565….
1.369369369369….
Tuesday, March 29, 2011
Thursday, March 24, 2011
Tuesday, March 22, 2011
8.3 Geometric Sequences
Intro
http://www.youtube.com/watch?v=C7tE26CDI2M
Formula for nth term
http://www.youtube.com/watch?v=IGFQXInm-co&feature=relmfu
Infinite sum and repeating decimals
http://www.youtube.com/watch?v=7GNTz2CbPYs
http://www.youtube.com/watch?v=nDm74LdP54w
http://www.youtube.com/watch?v=C7tE26CDI2M
Formula for nth term
http://www.youtube.com/watch?v=IGFQXInm-co&feature=relmfu
Infinite sum and repeating decimals
http://www.youtube.com/watch?v=7GNTz2CbPYs
http://www.youtube.com/watch?v=nDm74LdP54w
Monday, March 21, 2011
8.2 Arithmetic Sequences
Intro
http://www.youtube.com/watch?v=ZtPsWriHwa8
Formula for nth term
http://www.youtube.com/watch?v=lj_X9JVSF8k
Finding the Sum of an arithmetic sequence
http://www.youtube.com/watch?v=UHkueFmPC6s
http://www.youtube.com/watch?v=ZtPsWriHwa8
Formula for nth term
http://www.youtube.com/watch?v=lj_X9JVSF8k
Finding the Sum of an arithmetic sequence
http://www.youtube.com/watch?v=UHkueFmPC6s
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