BITSAT2016MathematicsTrigonometric EquationsActual
The general solution of the equation 2 x+2 x+2 x+1=0 is
Options
- A3 n - 4
- B2 n + 4
- C2 n +(-1)^ n ⁻¹ ( 1 3 )
- Dn - 4
Correct answer
D. n - 4
Step-by-step solution
Given, 2 x +2 x +2 x +1=0 1+ 2 x +2( x + x )=0 ( x+ x)²+2( x+ x)=0 ( x+ x)( x+ x+2)=0 x+ x=0 or x+ x=-2 But, x+ x=-2 is inadmissible. Since, | x| 1,| x| 1 x+ x=0 (x+ 4 )=0 x+ 4 =n x=n - 4