When learning about the ambiguous case for law of sines my algebra 2 textbook explains how to find the obtuse option by subtracting your answer from 180. This would mean (using this example) that there are two possible triangles A=46, B=65.93, B=68.07 OR the obtuse case where we take C=180-65.93= 114.07, A=46, and B=19.93. This is the same result you got using strictly the law of cosines.... so why would this be incorrect? Both triangles are possible solutions since it IS ambiguous. Can you help me figure out why the acute case is not a valid solution?
Great suggestion. One other way of doing it if you use the Law of Sines is to solve for the smallest angle first. What I try to do to teach this is have one half of the class to solve for one angle first and the other half solve for the other angle first, then get together and try to figure out what happened to give them different answers. Then you'll get the correct obtuse angle by subtraction from 180. Seeing that is a lot easier if you draw that triangle roughly proportionately from the start. Thanks.
Thank you
Right on time, I have a test on this tomorrow!
Thanks
Thankyou sir!
Most welcome!
When learning about the ambiguous case for law of sines my algebra 2 textbook explains how to find the obtuse option by subtracting your answer from 180. This would mean (using this example) that there are two possible triangles A=46, B=65.93, B=68.07 OR the obtuse case where we take C=180-65.93= 114.07, A=46, and B=19.93. This is the same result you got using strictly the law of cosines.... so why would this be incorrect? Both triangles are possible solutions since it IS ambiguous. Can you help me figure out why the acute case is not a valid solution?
photos.app.goo.gl/tnZbedXuxW3tRvAh7
Thanks Mr.Mclogan! 🎊🎉
you are very welcome!
Great suggestion. One other way of doing it if you use the Law of Sines is to solve for the smallest angle first. What I try to do to teach this is have one half of the class to solve for one angle first and the other half solve for the other angle first, then get together and try to figure out what happened to give them different answers. Then you'll get the correct obtuse angle by subtraction from 180. Seeing that is a lot easier if you draw that triangle roughly proportionately from the start. Thanks.
Love it! Haha yes "drawing not to scale" always seemed to pop up haha
No way I caught a post this early wild
boom!
School never taught me this