f ( theta ) = 2 sec ( theta ) + tan ( theta )
0 <= theta < 2 pi
f ' ( theta ) = sec ( theta ) * [ 2 tan ( theta ) + sec ( theta ) ]
set derivative to 0 to find critical numbers.
sec ( theta ) * [ 2 tan ( theta ) + sec ( theta ) ] = 0
The only way I know how to do this problem is to plug different angle values for theta. The values that
satisfy the equation are critical numbers.
Is there a better way to do this problem ? Is there a method or procedure ?
This problem is from Advanced Placement High School Calculus class.