Question 122488
{{{3v^2+4v-1=0}}}
Use the quadratic formula.
 {{{v = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
 {{{v = (-4 +- sqrt( 4^2-4*3*(-1) ))/(2*3) }}}
{{{v = (-4 +- sqrt( 16+12 ))/(6) }}}
{{{v = (-4 +- sqrt( 28 ))/(6) }}}
{{{v = (-4 +- 2sqrt( 7 ))/(6) }}}
{{{v = (-2 +- sqrt( 7 ))/(3) }}}
The exact roots are, 
{{{v[1] = (-2 + sqrt( 7 ))/(3) }}}
{{{v[2] = (-2 - sqrt( 7 ))/(3) }}}
or approximately,
{{{v[1] = 0.215 }}}
{{{v[2] = -1.549 }}}

{{{drawing( 300, 300, -3, 3, -3, 3,grid( 1 ),circle(.215,0,.15),circle(-1.549,0,.15),graph( 300, 300, -3, 3, -3, 3, 3x^2+4x-1) )}}}