Solve the equation on the interval 0 lessthanorequalto theta

Solve the equation on the interval 0 lessthanorequalto theta

Solution

1) 2costheta +3 = 2

costheta = -1/2

theta = pi -pi/3 , pi +pi/3

theta = 2pi/3 , 4pi/3

2) f(x) = 4csctheta - 2 ;

f(x) =2 ; 4csctheta - 2 = 2

4csctheta = 4

csctheta = 1

1/sintheta = 1

sintheta = 1

theta = pi/2