Question 172484
{{{y = x^2 + 4x - 1}}}
Solve by Quadratic:
where------->{{{system(a=1,b=4,c=-1)}}}
Then,
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}
{{{x=(-4+-sqrt(4^2-4*1*-1))/(2*1)=(-4+-sqrt(16+4))/2}}}
{{{x=(-4+-sqrt(20))/2=(-4+-4.472136)/2}}}
2 values:
{{{x=(-4+4.472136)/2=0.472136/2=highlight(0.2360679)}}}
{{{x=(-4-4.472136)/2=-8.472136/2=highlight(-4.236068)}}}
let's see the graph:
{{{drawing(400,400,-5,5,-7,5,graph(400,400,-5,5,-7,5,x^2+4x-1),blue(circle(0.2360679,0,.15)),blue(circle(-4.236068,0,.15)))}}}
Thank you,
Jojo