Question

i need help understanding The law of cosines and The law of sines

Answer 1

okay, law of sine is (Sin A) / sin a = (Sin B) / sinb.

law of cosine is a2 = b square - c square -2 (b)(c) cos (degree)

Answer 2

okay thats great but i need help to completely understand them....

Answer 3

which part do you need help exactly cause be a little specific

Answer 4

okay well my assignment is to describe when to use the law of cosines, the law of sines, and the law of sines with the ambiguous case. and i have to provide general guidelines for each law so that it can be applied to any triangle that someones given....

Answer 5

The Law of Cosines is
c² = a² + b² - 2abcosΘ.
It has four variables; a, b, c and Θ.
Whenever you have a triangle with three of these variables known, use the Law of Cosines to calculate the unknown variable.

The Law of Sines is
a/sinA = b/sinB = c/sinC
Although it has six variables, when you use it, you only need four.
You can use a/sinA = b/sinB, or a/sinA = c/sinC, or b/sinB = c/sinC.
Whenever you have a triangle with three of those four variables known, you use the Law of Sinces to calculate the unknown variable.

Because the sine of an angle is equal to the sine of the supplement of that angle, that is an ambiguity. Therefore, when you use the Law of Sines, you have two values for each sine. One will be an acute angle and one will be an obtuse angle. These two angles will be supplements of each other. In other words, the sum of these two angles = 180º

Answer 6

iono if that helps you?

Answer 7

naw i already found that .-.

Answer 8

oh

Answer 9

can u send me ur sheet?

Answer 10

yeah.......here ill give you a medal for at least trying thx :/

Answer 11

no problem

Answer 12

Okay. The law of cosines is used when you have a two sides and the angle between them. The law of sines is used when you have 2 sides and an angle, or 2 angles and a side. The sides MUST be across from the angles in the triangle, though.