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koli123able
Group Title
If the equation x^2+(7+a)x+7a+1=0 has equal roots,find the value of a.
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ANSWER = {9,5}
 2 years ago
 2 years ago
koli123able Group Title
If the equation x^2+(7+a)x+7a+1=0 has equal roots,find the value of a. . . . ANSWER = {9,5}
 2 years ago
 2 years ago

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koli123able Group TitleBest ResponseYou've already chosen the best response.0
how should i start
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
For a root with multiplicity two you need to need to have the discriminant equal to 0.
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
D=b^24ac
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
So what I'm saying is: \[Ax^2+Bx+C=0 => \text{ discriminant } = B^24AC\] And we want here for the discriminant=0
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
but what is b and a and c the equation is a bit confusing
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
Since we want root with multiplicity 2 :) So \[B^24AC=0\]
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
\[\text{ you have } x^2+(7+a)x+(7a+1)=0\]
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
A is the number in front of x^2 B is the number in front of x C is the leftover part
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
\[x^2+(7+a)x+7a+1=0\]
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
A=1 B=(7+a) c=(7a+1)
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
\[(7+a)^24(1)(7a+1)=0\]
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
That is B^24AC=0 You think you can solve that reply above for a?
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
ok wait
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
49+14a+a^214a+4=0
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
I think you mean 28a since 4(7)=28 not 14
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
yeah 28a
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
a^214a+53=0
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
is it right
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
well .... I think your 53 is a little off. you have 494 you forgot to distribute that  earlier
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
\[49+14a+a^24(7a+1)=0\] \[49+14a+a^228a4=0\] Now try combining like terms.
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
a^214a+45=0
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
yep do you know how to factor?
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
yep but i am solving this with quadratic is it ok?
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
The quadratic formula? That is fine. :)
 2 years ago

Miyuru Group TitleBest ResponseYou've already chosen the best response.0
I solved it by factors..
 2 years ago

Miyuru Group TitleBest ResponseYou've already chosen the best response.0
thnx @myininaya U are great. Nice help
 2 years ago

koli123able Group TitleBest ResponseYou've already chosen the best response.0
got 2 values 9 and 5 of a
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
Great! You go guys! :)
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
If you guys didn't understand why I set the discriminant equal to 0, then I will try to explain as best as possible. If discriminant is equal to 0, then you will have on root (multiplicity 2) If discriminant is equal to negative number, you have two imaginary solutions If discriminant is equal to positive number, you have two real solutions.
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
The discriminant is \[B^24AC \]
 2 years ago

Miyuru Group TitleBest ResponseYou've already chosen the best response.0
How did it came.
 2 years ago

Miyuru Group TitleBest ResponseYou've already chosen the best response.0
@myininaya how to solve the equation to get the discriminant..
 2 years ago

myininaya Group TitleBest ResponseYou've already chosen the best response.2
\[x=\frac{b \pm \sqrt{b^24ac}}{2a} \text{ is called the quadratic formual } \] The discriminant is that thing under the radical It is what determines if you have one root (w/ multiplicity 2) , imaginary roots, or real roots.
 2 years ago

Miyuru Group TitleBest ResponseYou've already chosen the best response.0
So to slove the equation should i find a b c
 2 years ago
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