How would you know when to use Sine law?
You can use Sine Law if:
here is the formula:
(c) world book Inc. - mathemagic vol 18
Hi Gummy Bears | #1 A trick for 2007 only 1. First pick the number of days of the week that you would like to go to the movies with your friends. 2. Multiply this number by 2. 3. Add 5. 4. Multiply it by 50. 5. If you have already had your birthday this year, add 1748. If you have NOT had your birthday, then add 1747. 6. Subtract the four digit year that you were born. 7. You should now have a three digit number (or a two digit number if you picked 0 for the number of times to go to the movies). The first is the number of times you want to go the the movies (it is 0 as previous). The second two are your age!!! Pretty cool huh!!! |
The answer's format is: month/day/year. For example, an answer of 123199 means that you were born on December 31, 1999. If the answer is not right, you followed the directions incorrectly or lied about your birthday.
Labels: janelle, math trick, scribe
Labels: Jenny, math trick, scibe
What do you get? Your age repeats 3 times.
Watch this: 28 (age) x 7 = 196.
196 x 1443 = 282828!
Actually, what you're doing is multiplying your age by 10101. Your age will repeat 4 times if you multiply it by 1010101. Notice the number of ones? Yep, four, hence four age repetitions.
What if you're age 9 and younger? Does this still work? Well....sort of. You get 90909, or really, 090909. To really enjoy this, though, it helps to be 10 and older.
Labels: cosine law
Labels: scibe
a2 = b2 + c2 - 2bc CosA
** Use this formula when you do not have a complete set of ratios ( a length of a side with its corresponding angle ).
Only use this formula (it's confusing & long) ONCE, and then use the sine law or any other formula to help you complete the trig question you have.
a2 = b2 ="b + c2 - 2bc CosA
a2 = (7.8)2 + (9.0)2 - 2(7.8)(9.0)Cos112
a2 = 60.84 + 81 - (-52.5947)
a2 = 194.44
a2 = √194.44
a = 13.9
Labels: cosine law, Jenny, sribe
Labels: janelle, scribe, trigonomety/geometry
So far we've only been able to work with right-angle triangles when using trigonometric functions. Although these are really useful triagles, there are lots of other types of trinangles besides right angles. We need a way to deal with those.
If we're working with a non-right angle triangle, that means there's no hypotenuse, so we can't use Pythagorean theorem. Instead, we have 2 tools called the Sine Law and the Cosine Law. Let's take a look at the Sine Law first
If we have this triangle:
.
The Sine Law says that its sides and angles are related in this way:
a b c
------- = ------- = -------
sin A sin B sin C
Main points to notice:
the triangle needs to be labelled the way it is in the picture above: side a is opposite angle A, side b is opposite angle B, and side c is opposite angle C (note - c is NOT the hypotenuse)
Thank you!!!!