- two *x*atan(x - one)/(x^ two - one)^ two + one /((x^ two - one)*((x - one)^ two + one)) = zero
minus 2 multiply by x multiply by arc tangent of gent of (x minus 1) divide by (x squared minus 1) squared plus 1 divide by ((x squared minus 1) multiply by ((x minus 1) squared plus 1)) equally 0
minus two multiply by x multiply by arc tangent of gent of (x minus one) divide by (x to the power of two minus one) to the power of two plus one divide by ((x to the power of two minus one) multiply by ((x minus one) to the power of two plus one)) equally zero