# i need help .really need to understand how to do this step by step. plz help someone. Question 7

#### ksdhart2

##### Senior Member
You're told that this particular polynomial has two equal roots. In order for this to be the case, what must be true about the discriminant of the polynomial? Which value(s) of $$a$$ ensure this condition holds?

#### dev644

##### Junior Member
OK thanks, I have solved it. Great community, keep the good work

#### Denis

##### Senior Member
Could you post your solution: it may help another student.
Thank you.

#### pka

##### Elite Member
Find the value of $$\displaystyle a$$ that causes $$\displaystyle (3a-2)x^2-6ax+4a+1=0$$ has a double root.
To have a double root the discriminate must be zero:
$$\displaystyle \Delta=(-6a)^2-4(3a-2)(4a+1)=0$$ SEE HERE

If $$\displaystyle a=2$$ the root is $$\displaystyle 1.5$$ SEE HERE

If $$\displaystyle a=\frac{-1}{3}$$then the root is $$\displaystyle \frac{1}{3}$$ SEE HERE

#### Denis

##### Senior Member
well...in other words...b^2 = 4ac

#### dev644

##### Junior Member
Why are u angry jomo?