Weekly Reflection 10-26-18

The Law of Sine and Cosine:
I will be able to use law of Cosine and law of Sine.


                                                         Example of law of Cosine:                                                         

                                                    
        Solve for C: a=2 b=3 C=60 degrees     
 In order to solve I need to figure out whether the equation is sine or cosine. The triangle is cosine  has Side Angle Side. Because it is a cosine problem I will use the cosine formula{c^2=a^2+b^2-2ab cos C}. To solve I will take the information that the problem gives me and plug it in to the equation after plugging all of the variables I have C^2= 4+9-2(2)(3)cos (60) instead of simplifying I can just plug this all in to the calculator then I will have C^2=24.42895576.    I am not done yet I still need to square root both sides. C is approximately 4.95                                                                  

Example of law of sine:


Solve the triangle: A=40 degrees, B=60 degrees, and a=4
In order to solve I need to figure out whether the equation is sine or cosine. I know the equation is sine because it has Angle Angle Side. Because it is sine I need to use the sine formula which is
Sin A = Sin B (basically a proportion). To solve I need to plug in the information that the problem
    a           b 
gives me so Sin (40) =Sin (60) I need to cross multiply to get b sin (40)= 4 sin (60) then I need to
                         4              b             
to divide by sin (40) by 4 sin (60) and put it on the calculator to get approximately 5.39 


One misconception I had was when doing law of cosine I was unsure on what to do if I had everything on one side of the equal sign.  I was simplifying when in reality all I had to do was put it in the calculator. I knew I had to be doing something wrong because I was getting different answers then everyone else. I overcame my misconception when I asked Mrs.Burton to help me out because I was confused. She helped me understand that all I had to do was put everything in the calculator and let the calculator do the work for me.


 EQ- How do I use law of sines and cosines in order to find missing parts of non-right triangles?
In order to find missing parts of non-right triangles using law of sine the triangle has to be either Side Angle Side, Angle Angle Side, Angle Side Angle, or Side Side Angle. Once you've figured out which one it is you plug in the information you know into the proportion  Sin A = Sin B
                                                                                                 a            b
you don't have to use the same variables use these exact variables you can change it based on what angle or side you have. Then solve for the missing side or angle. In order to solve to find missing parts of non-right triangles using law of cosine the triangle has to be Side Side Side or Side Angle Side. Once you've figured out which one it is you plug in the information you know into the equation c^2 = a^2 + b^2 - 2(a)(b) cos(C) you don't have to use these exact variables you can change it based on what angle or side you have. Then solve for the missing side or angle.




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