SOLUTION: Find the exact value of cos225° using 2 different formulas.
Please note: I tried using both the double and half angle formulas but I can't seem to get the answer. Your help woul
Algebra ->
Trigonometry-basics
-> SOLUTION: Find the exact value of cos225° using 2 different formulas.
Please note: I tried using both the double and half angle formulas but I can't seem to get the answer. Your help woul
Log On
Question 867731: Find the exact value of cos225° using 2 different formulas.
Please note: I tried using both the double and half angle formulas but I can't seem to get the answer. Your help would be greatly appreciated. With detailed steps so I can learn from it too. Thanks! Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Find the exact value of cos225° using 2 different formulas.
---------
Use cos(225) = -cos(45)
AND
Use cos(225) = cos(180+45)
==============================
Cheers,
Stan H.
--------------------
(