9000046505

SubArea: 
Trigonometric equations and inequalities
Level: 
C
Project ID: 
9000046505
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. \[ \sin x = 1 +\cos x \]
\(\sin ^{2}x = 1 + 2\cos x +\cos ^{2}x\)
\(\sin ^{2}x = 1 +\cos ^{2}x\)
substitution \( 1 +\cos x = z\)
\(\sin x -\cos x = z\)