SOLUTION: using pythagorean identity to siplify the following expressions. a) cos^2 30 degrees + sin^2 30 degrees b) cos^2 50 degrees + cos^2 40 degrees c) 1 - sin^2 20 degrees

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Question 596101: using pythagorean identity to siplify the following expressions.
a) cos^2 30 degrees + sin^2 30 degrees
b) cos^2 50 degrees + cos^2 40 degrees
c) 1 - sin^2 20 degrees

Answer by richard1234(7193)   (Show Source): You can put this solution on YOUR website!
a) 1
b) cos^2 (40) = sin^2 (50), 1
c) Rewrite 1 as sin^2 (20) + cos^2 (20), ans is cos^2 (20)

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