Integrate cos(2theta)d(theta) from 0 to pi/5

Find the vertex of the function given below y=x^2-6x+1

A3-dimensional figure has a square base and 4 lateral faces that meet at a point. explain the difference between the cross sections when a slice is made perpendicular to the base through the vertex, and when a slice is made perpendicular to the base and not through the vertex

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?