Answer:
Explanation:
Volume of the trough = area of the end part * 20
= 20 (cosO)/2 *((1 + (1 + 2sinO) + 1)
= 10 cosO (2 + 2 sinO)
= 20 cosO(1 + sinO)
You can now find the value of angle O for maximum volume by drawing a graph of the above function by hand or using on-line software.
The value comes to 30 degrees.