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# Need help with a maths question! Watch

1. 1)Solve the equation - modulus(x) + sqrt(x+4) - 2=0
Also I have another question which in 'Essential Maths for Economic Analysis' is 2.2.4, and it is the one with K,L, r and w as varaibles/parameters. I have to find K(L).

Any help would be appreciated, as I am really struggling with this module.

Thanks,

Paul
2. Square everything perhaps?
3. I've tried that, but then go to use the quadratic formula and get a negative discriminant
4. Have you studied complex numbers?
5. I am not sure, I have studied the modulus before. I have MEI A level maths at an A grade.
6. (Original post by paul_blakeman)
I am not sure, I have studied the modulus before. I have MEI A level maths at an A grade.
What did you get for the discriminant?
7. (Original post by xCBRx)
What did you get for the discriminant?
(1-(4x1x8)) = -31
8. (Original post by paul_blakeman)
(1-(4x1x8)) = -31
That seems like you've squared each term seperately, which you can't do. If you want to square it to get rid of the square root:

Modulus(x) + Sqrt(x + 4) - 2 = 0
Sqrt(x + 4) = 2 - Modulus(x)

Then square it

x + 4 = 4 - 4Modulus(x) + x^2

and then work it out from there. I haven't done much with the modulus function, but I would assume that Modulus(x)^2 = x^2, as x^2 always positive?
9. Yeah thanks for your help.

Have repped

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