Question

20 Point!

Answer 1

determinant: $\sqrt{b^2-4ac}$

(a) $x^2+4x+5=0\\D=4^2-4\cdot1\cdot5={-4}\\D$

D<0 means there are no real roots. there are two complex roots with imaginary components.

(b) D=16+20=36>0

D>0 means there are two real roots

(c) D = 20^2-4*4*25 = 0

D=0 means there is one real root with multiplicity 2