Question 141112
ax^2+bx+c=0 is a quadratic equation
The discriminant is b^2-4ac. If it is negative then its square root will not be real and its 2 roots will be imaginary. If it is positive there are 2 real roots. If it is zero then there is one real root.
a=1, b=4, c=4
For the case at hand, 16-4*4=0 There is one real root.
x^2+4x+4=0
(x+2)^2=0
x=-2
-2 is the only root.
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Ed
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{{{graph(500,500,-10,10,-2,18,x^2+4x+4)}}}