Comments | calculus: The Unit Circle

seductivenerd in calculus

The Unit Circle

Sep 17, 2007 22:28

I know that the unit circle is soooo Pre-calculus, but it's causing me problems in my calculus class. There'll be questions that expect you to know the coordinates at a certain radian and what not. Are there and tips, tricks, etc, that you all can give me in remembering/learning the unit circle? I mainly need help with sectioning it different ways ( Read more... )

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reiben55 September 19 2007, 00:53:33 UTC

My teachers taught me a hand trick to remember the values of the basic numbers on the unit circle. You take your left hand and hold it with your palm facing you. Okay, all 5 fingers are like the five values of the first quadrant, so hold your hand like its the first Q. Pinky = 0, ring finger = 30, middle = 45, pointer = 60, and thumb = 90. In the middle of your palm is a 2. Say you want to find the sin of 30 degrees. You bend down your ring finger (the 30) and take the number of fingers below it. Sq. root those fingers and put it over the 2 in your palm. Ta da, you've got 1/2. To get the cos you sq. root the number of fingers (including thumb) above the 30 n put it over the 2. You get Sq. root 3 over 2. To find tan, you divide the sq. rooted sin fingers by the sq. rooted cos fingers. 1/sq. root 3 which equals root 3 over 3.

It's really weird to explain, but its so helpful. I would look at my hand constantly during a test and always got the answer.

seductivenerd September 19 2007, 00:57:06 UTC

Oh, that's really cool!

Awesome Trick Raven reiben55 October 21 2009, 19:50:01 UTC

Thanks for sharing that, I dig it and I think it will help me.

THANK YOU! reiben55 April 1 2010, 00:48:22 UTC

Ugh, I'm struggling to get this concept, facing a teacher I can't stand who won't help - "I taught the concepts, its your job to learn them.." so this little trick is a Godsend! LOL thank you so much :)

Awesome thank you!!! reiben55 May 28 2010, 01:26:41 UTC

I have a test on this subject and this is really going to help. Now i won't stress as much on units circles. Thanks!!!!!!!!!

a better palm trick reiben55 October 31 2010, 03:04:11 UTC

before entering a test, write the answers on your right palm.
then when you come accross a problem, hold your right and hold it up palm facing you. read answers.
write.

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