Double and half argument
1.Write formulas for double and half arguments:
Formulas:
sin 2x = 2x sin x . cos x
cos 2x = cos
2x – sin
2x
2.Calculate functions of double argument if:
Solution:
3.Simplify:
Solution:
4.Simplify:
Solution:
5.Calculate the trigonometric functions of the half angle if
Solution:
6.Simplify:
Solution:
7.Prove identity:
Solution:
Identita platí, ak x ≠ kπ
8.Prove identity:
Solution:
Identity proved when x ≠ kπ
9.Prove that it is valid:
Solution:
Identity proved when x ≠ kπ
10.Show that the identity holds:
Solution:
