The cosine of z in Math. Defined by
\[ \cos z = \frac{ e^{iz} + e^{-iz} }{ 2 } \]Real part on the real axis:
Imaginary part on the real axis is zero.
Real part on the imaginary axis:
Imaginary part on the imaginary axis is zero.
Real part on the complex plane:
Imaginary part on the complex plane:
Absolute value on the complex plane:
Related functions: sin sec arccos
Function category: circular functions