The quadratic x2 + 20x + 100 has what type of roots? A.Two Irrational B.Two Complex C.Two Rational D.One Rational Double

Question

The quadratic x2 + 20x + 100 has what type of roots?   A.Two Irrational   B.Two Complex   C.Two Rational   D.One Rational Double

anonymous · Answer

I got One Rational Double, but i dont think its right and need help!

anonymous · Answer

It's right. The discriminant equals zero, thus 1 real solution. 

x=-10...twice

anonymous · Answer

THANKS!

anonymous · Answer

welcome

unklerhaukus · Answer

When you have a parabola(quadratic) that is of this form$$y=ax^2+bx+c$$its  discriminant is  $\Delta=b^2−4ac$

There are three cases
$\Delta<0$ will not touch x axis - there will be no real solutions
$\Delta=0$ will touch x axis at one place only - one solution
$\Delta>0$ will touch x axis exactly twice - two solutions

in your case $a=1,b=20,c=100$
$$\Delta=20^2−4(1)(100)=400-400=0$$