Question 155981
y=x^2+4x-1
{{{ graph( 300, 200, -6, 5, -10, 10, x^2 +4x +1) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, x^2 +4x +1). 
Using the quadratic equation {{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} we get:
x=0.236 & -4.236