NTA Abhyas JEE Main2020MathematicsTrigonometric EquationsPractice
The number of solutions of the equation sin 3 x cos x + sin 2 x cos 2 x + cos 3 x sin x + 1 = 0 in the interval 0 , 2 π is equal to
Options
- A0
- B2
- C4
- D8
Correct answer
A. 0
Step-by-step solution
The given equation can be written as sin x cos x sin 2 x + cos 2 x + sin 2 x cos 2 x + 1 = 0 Substituting t = sin x cos x in this equation, we get t 2 + t + 1 = 0 . This equation has no real roots.