for the quadratic ax2+bx+c to have two distinct roots b2−4ac>0
Thanks! I understand that but I just honestly don't understand how to figure this whole thing out :/ I can't really find any good examples online and it's just really confusing me.
Thanks! I understand that but I just honestly don't understand how to figure this whole thing out :/ I can't really find any good examples online and it's just really confusing me.
In your quadratic what do you think a=, b= and c= ?
Thanks! I understand that but I just honestly don't understand how to figure this whole thing out :/ I can't really find any good examples online and it's just really confusing me.
do you understand the quadratic formula, or at least how it gets you the roots of a quadratic?
well the quadratic formula tells us that the roots of the quadratic equation ax2+bx+c=0 are x=2a−b±b2−4ac
As you know you cannot square root a negative number so in order for real roots to exist the part under the square root sign must be > 0.
If the part under the square root is zero we end up with x=2a−b±0 which means both roots are the same. You still get 2 roots but they are same ie not distinct roots.
Finally if the part under the sqaure root is positive then you get two distinct roots, namely x=2a−b+b2−4ac and x=2a−b−b2−4ac
In Summary;
So if a quadratic has no real roots then the part under the square root sign is negative ie b2−4ac<0
If a quadratic has a repeated root (this means both x values you find from the quadratic formula are the same) then the part under the square root sign is equal to 0 ie b2−4ac=0
Finally if a quadratic has two distinct roots then the part under the square root is > 0 ie b2−4ac>0
I hope this clears it up at least a little for you
do you understand the quadratic formula, or at least how it gets you the roots of a quadratic?
well the quadratic formula tells us that the roots of the quadratic equation ax2+bx+c=0 are x=2a−b±b2−4ac
As you know you cannot square root a negative number so in order for real roots to exist the part under the square root sign must be > 0.
If the part under the square root is zero we end up with x=2a−b±0 which means both roots are the same. You still get 2 roots but they are same ie not distinct roots.
Finally if the part under the sqaure root is positive then you get two distinct roots, namely x=2a−b+b2−4ac and x=2a−b−b2−4ac
In Summary;
So if a quadratic has no real roots then the part under the square root sign is negative ie b2−4ac<0
If a quadratic has a repeated root (this means both x values you find from the quadratic formula are the same) then the part under the square root sign is equal to 0 ie b2−4ac=0
Finally if a quadratic has two distinct roots then the part under the square root is > 0 ie b2−4ac>0
I hope this clears it up at least a little for you
Thank you for explaining it out like that! The question is starting to make more sense for me!
Thank you for explaining it out like that! The question is starting to make more sense for me!
youll get by if you learn off the summary part at the bottom. Just know whether to use b2−4ac>0 ,b2−4ac=0 , b2−4ac<0 depending on whether they ask for 2 distinct roots, 1 repeated root or 0 real roots