[blindkid] Unit Cirlce - Sharing Solution

Kim Cunningham kim at gulfimagesphoto.com
Thu Oct 1 11:54:47 UTC 2009


Good morning all,
Yesterday I posted a question concerning how to read the "Unit Cirlce" in my daughter's pre-calculus class. One of her blind friends emailed her a solution and I thought I would share it with y'all. You might want to save this bit of info if your child will be taking the class in the next year or two.
Regards,
Kim Cunningham
 
Hey Kayleigh,
It's Melissa.
I had a cool Prof for college buisness Cal last semester and she
taught me a cool trick using my fingers 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.

Also, if you can access and use Excell try doing the following to find
solutions. I know a lot of VI and/or blind people find Excell very
useful.

π = 180°

Write down the following values as column headings

|0°|30°|45°|60°|90°

Write down the following values as row headings

sin(x)
cos(x)
tan(x)

So, you should have 15 empty spaces (5 columns times 3 rows)

On the first row AND second row, write:

√()/2 √()/2 √()/2 √()/2 √()/2 (you're leaving the stuff under the
square root blank)

For the first row (sin(x)'s row), write

√(0)/2 √(1)/2 √(2)/2 √(3)/2 √(4)/2

Simplify if you want to

For the second row (cos(x)'s row), go backwards from sin(x)

√(4)/2 √(3)/2 √(2)/2 √(1)/2 √(0)/2

Simplify if you want to

tan(x) = sin(x)/cos(x), so generate tan(x)'s values that way.

On the unit circle, cos(x) corresponds to X and sin(x) corresponds to
Y. The values we generated earlier are the reference angle
measurements from the X-axis. cos(x) is + in QI&QIV, sin(x) is + in
QI&QII. tan(x) is + in QI&QIII.

I hope at least one of these methods helps you out.



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