The number of Solutions of the equation Tan−1x−1+Tan−1x+Tan−1x+1=Tan−13xis /are
4
3
2
1
We have Tan-1x-1+Tan-1x+Tan-1x+1=Tan-13x
⇒Tan−1x−1+Tan−1x+1=Tan−13x−Tan−1x
⇒Tan-1x-1+x+11-x-1x+1=Tan-13x-x1+3xx ⇒2x2-x2=2x1+3x2 ⇒2x1+3x2-2+x2=0 ⇒x=0,x2=14 ⇒x=0, x=±12