Double and half argument

1.Write formulas for double and half arguments:

Formulas:
sin 2x = 2x sin x . cos x
cos 2x = cos2x – sin2x
argument1

2.Calculate functions of double argument if:

argument2ak
Solution:
argument2r

3.Simplify:

argument2ak
Solution:
argument3r

4.Simplify:

argument2ak
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5.Calculate the trigonometric functions of the half angle if

argument5ak
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6.Simplify:

argument6
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7.Prove identity:

argument7
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8.Prove identity:

argument8
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9.Prove that it is valid:

argument9
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10.Show that the identity holds:

dvojnasobny-a-polovicny-argument-10z.gif
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