Does anyone know how to know which of the graphs of these equations has no x-intercepts?

a)6x^2+2x-5=0
b) 4x^2-3x+1=0
c)4x^2-7x+3=0
d)x^2+8x-3=0

Question

Does anyone know how to know which of the graphs of these equations has no x-intercepts?

a)6x^2+2x-5=0
b) 4x^2-3x+1=0
c)4x^2-7x+3=0
d)x^2+8x-3=0

jdoe0001 · Answer

check their roots, see which ones give you imaginary values

jdoe0001 · Answer

imaginary values, means it has no x-intercepts or roots

anonymous · Answer

wait, how do u check its root?

amoodarya · Answer

$$x=\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }$$

jdoe0001 · Answer

hmm   well, you can always use the quadratic equation for one

ahemm.... anyhow.. the exercise assume you know how to factor quadratics

jdoe0001 · Answer

I assume you dunno the quadratic equation?

anonymous · Answer

oh I know the quadratic equation, but how does it help to find the x-intercept?

amoodarya · Answer

|dw:1390161750146:dw|