If tan−1x+tan−1y+tan−1z=π2,then xy+yz+zx=
1
2
3
4
If A+B+C=π2, then tanA . tanB + tanB . tanC + tanC . tanA = 1
tan−1x+tan−1y+tan−1z=π2⇒1−xy−yz−zx=
If tan−1x+tan−1y+tan−1z=π2 then prove that xy+yz+zx=1.