cis90

cis90 is a term that can refer to a chemical compound or a mathematical concept depending on the context. In organic chemistry, "cis90" is not a standard nomenclature. Chemical compounds are typically named using IUPAC (International Union of Pure and Applied Chemistry) rules, which provide systematic names based on molecular structure. If "cis90" is encountered in a chemical context, it might be a shorthand, a research code, or a specific identifier within a particular laboratory or database. Without further information, it is difficult to identify a specific chemical structure associated with this term.

In mathematics, "cis90" likely refers to the complex number cis(90°), which is a shorthand for cos(90°) + i sin(90°). The cis function is commonly used in complex number theory and trigonometry. Evaluating this expression, we find that cos(90°) is 0 and sin(90°) is 1. Therefore, cis(90°) simplifies to 0 + i(1), which is equal to the imaginary unit 'i'. This complex number has a magnitude of 1 and an angle of 90 degrees (or π/2 radians) with respect to the positive real axis in the complex plane. It represents a rotation by 90 degrees counterclockwise in the complex plane.