sgn r , | s | {\displaystyle \operatorname {sgn} r,\left\vert s\right\vert }
x = √ 2 + exp 3 {\displaystyle x=\surd 2+\exp _{3}}
f = z × ∫ x d y d x {\displaystyle f=z\times \int x{dy \over dx}}
