Problem : 
Solve the following equation:  sin(x)tan(x) = 0.
Solving 
sin(x) = 0, 
x = 0, Π.  Solving 
tan(x) = 0, the same solutions 
are reached.  
x = 0, Π.
 
Problem : 
Solve the following equation:  cos(x) - tan2(x) = 1.
Using the identity 
1 + tan2(x) = sec2(x), the equation 
cos3(x) = 1 
results.  Therefore 
cos(x) = 1, and 
x = 0.
 
Problem : 
Solve the following equation:  sin2(x) - 1 = cos2(x) + 2.
Using the identity 
sin2(x) + cos2(x) = 1, the equation 
sin2(x) = 2 
results.  This equation has no solution.
 
Problem : 
Solve the following equation:  2 sec(x)sin3(x) =  cos(x)tan2(x).
cos(x)tan2(x).
Resolving everything into sines and cosines and then cancelling, we have 
sin(x) = 
.  
x =  ,
,
.
 
Problem : 
Solve the following equation:  sin(x) + sin(x)cot2(x) = sec2(x) - tan2(x).
Factoring on the right side and the use of identities leads to the equations 
sin(x) = 1. Therefore, 
x = 
.