How do you find the discriminant and how many solutions does x^2 + 8x + 16 = 0 have?

1 Answer
MeneerNask
Apr 29, 2015

Equations of the form Ax^2+Bx+C=0

Discriminant=D=sqrt(B^2-4AC)=8^2-4*1*16=0
which means there is one solution
For D>0 there would be two solutions,
for D<0 there would be no (real) solution.

Without working out the discriminant, it's fairly easy to see that:
->(x+4)^2=0->x=-4
In the graph you see the standard x^2-graph moved by -4
graph{x^2+8x+16 [-15.5, 4.5, -2.4, 7.6]}

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