Thypher: Solve the Equations

Solve the following equations to guess the word based on the common variables with which they are associated.

\frac{y}{sin (k x - ω t + ɸ)}

\frac{N}{f_{p} n_{e} f_{l} f_{i} f_{c} L}

\nabla x \vec{A}

sin (x) - x + \frac{x^{3}}{6} + \frac{x^{5}}{120}

\frac{V}{I}

\int \frac{\partial Q_{r e v}}{T}