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Maths homework help

Given the roots of the equation kx (squared) - 6x +3k=0. Find the value of k where k >0

I know you use the discriminant but i'm not sure what sign to use etc can anyone help please

Reply 1

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Original post by Misshussain23

Given the roots of the equation kx (squared) - 6x +3k=0. Find the value of k where k >0

I know you use the discriminant but i'm not sure what sign to use etc can anyone help please

Just use the discriminant and solve it, simple! And when it comes to the sign if its a negative then it will change.

Reply 2

aamirac

Use the discriminant. Remember the sign always changes to the opposite when multiplying it with a negative value.

Reply 3

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Original post by Misshussain23

Given the roots of the equation kx (squared) - 6x +3k=0. Find the value of k where k >0

I know you use the discriminant but i'm not sure what sign to use etc can anyone help please

Are you sure thats the correct question?
I've tried it myself and got this:

kx(squared) - 6x + 3k = 0
b(squared) - 4ac > 0

(-6)(squared) - 4 x k x 3k
36 -12k(squared) > 0
36 > 12k(squared)
3 > k(squared) ( Divided 36 by 12 )

But yea now I'm confused what to do if k>0 then it must have 2 solutions so wtf :s-smilie:

Actually I think I did it right .. you then
do the square root of both sides to give:

3(root sign) > k or k< 3(root sign)

I think thats it :biggrin: