Assertion: trigonometric function's value | /r/HasProperty | complex
Facets:
Source sentences:
text: The trigonometric functions $ \mathop{\rm tan} z $ and $ \mathop{\rm cot} z $ take all complex values except $ \pm i $: The equations $ \mathop{\rm tan} z = a $, $ \mathop{\rm cot} z = a $ each have infinitely many solutions for any complex number $ a