Let P(x, y, z) be a point in the first octant, whose projection in the x y -plane is the point Q. Let O P=γ; the angle between O Q and the positive x…

Let $\displaystyle P(x, y, z)$ be a point in the first octant, whose projection in the $\displaystyle x y$-plane is the point $\displaystyle Q$. Let $\displaystyle O P=\gamma$; the angle between $\displaystyle O Q$ and the positive $\displaystyle x$-axis be $\displaystyle \theta$; and the angle between $\displaystyle O P$ and the positive $\displaystyle z$-axis be $\displaystyle \phi$, where $\displaystyle O$ is the origin. Then the distance of $\displaystyle P$ from the $\displaystyle x$-axis is