Question 919876
{{{y = sqrt(x^2-5x-6)}}}


{{{x = sqrt(y^2-5y-6)}}}


{{{x^2 = y^2-5y-6}}}

{{{  y^2-5y-x^2-6=0}}}

{{{  y^2-5y-(x^2+6)=0}}}  use quadratic formula; note that {{{a=1}}},{{{b=-5}}}, and {{{c=-x^2-6)}}}


{{{y = (-(-5) +- sqrt( (-5)^2-4*1*(-(x^2+6)) ))/(2*1) }}}


{{{y = (5 +- sqrt( 25+4(x^2+6) ))/2 }}}


{{{y = (5 +- sqrt( 25+4x^2+24 ))/2 }}}


{{{y = (5 +- sqrt(4x^2+49))/2 }}}


{{{y = (1/2)(5 +- sqrt(4x^2+49)) }}}

or

{{{f^-1(x)= (1/2)(5 +- sqrt(4x^2+49)) }}}