A right circular cone has a base radius r cm and a vertical angle 2y^o. The height of the cone is

The larger value of y for which (y - 1)² = 4y - 7 is

If sin \(\theta\) = \(\frac{x}{y}\) and 0^o < 90^o then find \(\frac{1}{tan\theta}\)

Measurements of the diameters, in centimeters, in centimeters, of 20 copper spheres are distributed as shown below
\(\begin{array}{c|c} \text{Class boundary in cm} & \text{frequency} & \\\hline 3.35 - 3.45 & 3\\ 3.45 - 3.55 & 6\\ 3.55 - 3.65 & 7\\ 3.65 - 3.75 & 4\end{array}\)
What is the mean diameter of the copper spheres?