Find all real numbers in the interval 02 pi that satisfy the
Solution
1 ) 6 sec^2 theta tan theta = 8 tan theta
subtracting 8 tan theta from both sides
6 sec^2 theta tan theta - 8 tan theta = 0
taking gcf as 2 tan theta
2 tan theta ( 3 sec^2 theta - 4 ) = 0
2 tan theta ( sqrt 3 sec theta - 2) ( sqrt 3 sec theta + 2) = 0
tan theta = 0 , theta = 0 ,pi,2pi
or sqrt 3 sec theta - 2 = 0 , theta = 5pi/6 , 7pi/6
or sqrt 3 sec theta + 2 = 0 , theta = pi/6 , 11 pi/6
combining all solutions
theta = 0, pi/6 , 5pi/6 , 7pi/6,11pi/6 ,pi,2pi
2) 2 sin theta = cos theta
dividing both sides by cos theta
2 sin theta / cos theta = cos theta / cos theta
2 tan theta = 1
tan theta = 1/2
theta = tan^-1 ( 1/2 )
solutions are
theta = pi + .4636 , theta = .4636
3) 2 sin^2 x - 3 sin x = -1
add 1 to both sides
2 sin^2 x - 3 sin x + 1 =0
( sin x -1 ) ( 2 sin x -1 ) = 0
sin x = 1 , x = pi/2
, sin x = 1/2 , x = pi/6 , 5pi/6
combining the solutions
x = pi/2 , pi/6 , 5pi/6
factoring the equation

