Farmerjj
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Given that x^2 + 8kx +k =0 has equal roots

Find the value of K


I put it into b^2 - 4ac and so now have (8k)^2 - 4K = 0
What do I do next?
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the bear
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(Original post by Farmerjj)
Given that x2 + 8kx +k =0 has equal roots

Find the value of K


I put it into b2 - 4ac and so now have (8k)2 - 4K = 0
What do I do next?
now solve that mofo
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Shady778
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Make K the subject of the formula after applying the squared on 8k. giving you 64k^2 - 4k = 0 . Try and work from there
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Farmerjj
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(Original post by the bear)
now solve that mofo
How
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Farmerjj
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(Original post by Shady778)
Make K the subject of the formula after applying the squared on 8k. giving you 64k^2 - 4k = 0 . Try and work from there
Nope no idea sorry I don't see how you can get an answer from that
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Sir Cumference
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(Original post by Farmerjj)
How
If you expand it then you've got a quadratic equation that can be solved by factorising.

It's similar to how you would solve something like x^2-4x=0. How would you solve this?
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Farmerjj
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(Original post by notnek)
If you expand it then you've got a quadratic equation that can be solved by factorising.

It's similar to how you would solve something like x^2-4x=0. How would you solve this?
You would factorise to (X-2)(X+2)
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the bear
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(Original post by Shady778)
Make K the subject of the formula after applying the squared on 8k. giving you 64k2 - 4k = 0 . Try and work from there
now factorise into two brackets... or you could use the Quadratic Formula ?
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Sir Cumference
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(Original post by Farmerjj)
You would factorise to (X-2)(X+2)
No that would be for x^2-4 = 0.

For x^2-4x=0 you should take out a factor of x.

For 64k^2 - 4k = 0, take out a factor of 4k.
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Shady778
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(Original post by the bear)
now factorise into two brackets... or you could use the Quadratic Formula ?
Wrong person XD but yes OP do what this person has said
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Farmerjj
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(Original post by notnek)
No that would be for x^2-4 = 0.

For x^2-4x=0 you should take out a factor of x.

For 64k^2 - 4k = 0, take out a factor of 4k.
Cheers man thanks I've got it now, just had a brain dead moment but thanks you

(1/16) is correct?
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Farmerjj
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(Original post by the bear)
now factorise into two brackets... or you could use the Quadratic Formula ?
Done now cheers bear 🐻
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doon98
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64k^2-4k=0

k(64k-4)=0

k=0, 64k-4=0
64k=4
k=1/16

so, k=0 and k=1/16
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the bear
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(Original post by Shady778)
Wrong person XD but yes OP do what this person has said
:hat2:
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Shady778
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(Original post by Farmerjj)
Cheers man thanks I've got it now, just had a brain dead moment but thanks you

(1/16) is correct?
Its partly correct. However you are missing roots.
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the bear
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(Original post by doon98)
64k^2-4k=0

k(64k-4)=0

k=0, 64k-4=0
64k=4
k=1/16

so, k=0 and k=1/16
complete answers are discouraged :dontknow:
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Shady778
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(Original post by doon98)
64k^2-4k=0

k(64k-4)=0

k=0, 64k-4=0
64k=4
k=1/16

so, k=0 and k=1/16
Do avoid giving straight out answers as we'd prefer to try and explain them through it on TSR
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Indigo.Brownhall
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(Original post by doon98)
64k^2-4k=0

k(64k-4)=0

k=0, 64k-4=0
64k=4
k=1/16

so, k=0 and k=1/16
nice one doon bear
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