How to solve 13th question

Q13. The solution set of the inequation log1/3 (x2 + x + 1) + 1 > 0 is

         (A) (– , –2)  (1, +  )

         (B) [–1, 2]

         (C) (–2, 1)

         (D) (– )
 

Dear Student,

Please find below the solution

log13x2+x+1+1>0log13x2+x+1>-1as we know logab=c gives ac=bx2+x+1>13-1x2+x+1>3x2+x+1-3>0x2+x-2>0x2+2x-x-2>0xx+2-1x+2>0x-1x+2>0therefore x-1>0 and x+2>0or  x-1<0 and x+2<0x>1 and x>-2 or x<1 and x<-2the common set of the above conditionx<-2 and x>1Hence the solution set of given problem is x-,-21,
Regards,

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