9000046507

SubArea: 
Trigonometric equations and inequalities
Level: 
C
Project ID: 
9000046507
Accepted: 
1
Clonable: 
0
Easy: 
0
Identify the optimal first step convenient to solve the following trigonometric equation. Do not consider the step which is possible but does not help to solve the equation. 3cos⁡x=1−sin⁡x
3cos2⁡x=(1−sin⁡x)2
3cos2⁡x=1−sin2⁡x
substitution 1−sin⁡x=z
substitution cos⁡x=z