18.Which equation has imaginary roots?

Question

A)x^2-x-1=0 B)x^2-2=0 C)x^2+x+1=0 D)x^2-1=0

Answer 1

To figure this out, you need to find the discriminant which is
(b^2 - 4ac). If you're discriminant is negative, then you have imaginary roots.

A) (-1)^2 - (4)(1)(-1) = 5
B) (0)^2 - (4)(1)(-2) = 8
C) (1)^2 - (4)(1)(1) = -3
D) (0)^2 - (4)(1)(-4) = 16

C has imaginary roots.

Answer 2

C) x^2+x+1=0

Answer 3

A)x^2-x-1=0
Discriminant = 1+4 =5>0 , real solutions only


B)x^2-2=0
Discrimianant = 0 +4(2) =8 >0 , real solutions only

C)x^2+x+1=0
Discriminant = 1 -4 = -3 <0 only complex solutions
x1 = (-1 - i sqrt(3) )/2
x2 = (-1 + i sqrt(3) )/2



D)x^2-1=0

(x -1)( x+1)=0 : solutions are x = 1 and x =-1

**********************
Summary
C) has has complex roots

Answer 4

1x1-4(1)(1)= -3 <0

x^2+x+1=0

Answer 5

it particularly is in certainty a nature vs. nurture question utilized to faith. If "god" supposedly created the international, which comprise our organic and organic inclinations then why wouldnt we settle for god from start up? it particularly is quite quite exciting, and that i could desire to determine a logical non secular answer. I dont have self assurance in any faith so I cant even start to fathom how somebody is going to logically make sparkling this one. Oh, and to Catti-brie. . . . undesirable undesirable analogy. If some thing, it at as quickly as enables the dude's theory that nurture is what shapes a guy or female's faith, no longer nature. edit: mcshughes, speech is organic and organic because of means of actuality it particularly is our stepped forward variety of communique. communique is organic and organic and stumbled on from start up. babies can use sign language and CRYING to get their ingredient for the era of. Crying is the 1st ingredient a infant does as quickly as out of the womb. that's a verbal communique.

Answer 6

find middle^@-4Front*Back
aka b^2-4ac
If Pos, both are real
if 0, just one real root, no im roots
if neg, two im roots
A)the value is 5
B)the value is 4
C)the value is -3
D)the value is 4
So, C is the one with imaginary roots.

Or, you could graph it. THe one that doesn't intersect the x axis has imaginary roots.

Answer 7

C). Calculate the discriminant for each of these.
The equation has imaginary roots if and only if
the discriminant, b²-4ac of the equation ax²+bx+c is
negative.
The discriminants are:
A). 5
B). 8
C). -3
D). 4
The only one of these which is negative is C),
so this is the only equation with imaginary roots.