How do I evaluate the integral -LSB- math -RSB- \ int \ frac -LCB- cos -LRB- 6x -RRB- -RCB- -LCB- cos -LRB- 3x -RRB- * cos -LRB- 5x -RRB- -RCB- -LSB- / math -RSB- ?
What is integral of inverse of cos ?