SOLUTION: Simplify using trigonometric identities: a) 4sin2x cos2x b) (1+cos2x)/2 c) cos^2x-sin^2x d) cos^2x+sin^2x Please help me i have no clue how to do this!

Algebra ->  Trigonometry-basics -> SOLUTION: Simplify using trigonometric identities: a) 4sin2x cos2x b) (1+cos2x)/2 c) cos^2x-sin^2x d) cos^2x+sin^2x Please help me i have no clue how to do this!      Log On


   

Question 773438: Simplify using trigonometric identities:
a) 4sin2x cos2x
b) (1+cos2x)/2
c) cos^2x-sin^2x
d) cos^2x+sin^2x

Please help me i have no clue how to do this!
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Simplify using trigonometric identities:
a) 4sin2x cos2x
sin(2x) = 2sin(x)cos(x)
cos(2x) = cos^2(x)-sin^2(x)
-------
b) (1+cos2x)/2
= (1 + cos^2(x)-sin^2(x))
-------
c) cos^2x-sin^2x
= 1-sin^2(x)-sin^2(x) = 1-2sin^2(x)
------------------
d) cos^2x+sin^2x = 1
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Cheers,
Stan H.
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