MHB Solving Equation: x = sqrt(3x + x^2 - 3sqrt(3x + x^2))

  • Thread starter Thread starter mathdad
  • Start date Start date
Click For Summary
The equation x = sqrt(3x + x^2 - 3sqrt(3x + x^2) is solved by first squaring both sides, leading to x^2 = 3x + x^2 - 3sqrt(3x + x^2). Simplifying this results in -3x = -3sqrt(3x + x^2), which further simplifies to x = sqrt(3x + x^2). Squaring again gives x^2 = 3x + x^2, leading to the conclusion that 0 = 3x. The only real solution is x = 0, confirming the correctness of the solution process.
mathdad
Messages
1,280
Reaction score
0
Find all real solutions of the equation.

$x = \sqrt{3x + x^2 - 3\sqrt{3x + x^2}}$

Must I square each side twice to start?

$(x)^2 = [\sqrt{3x + x^2 - 3\sqrt{3x + x^2}}]^2$

$x^2 = 3x + x^2 - 3\sqrt{3x + x^2}$

$x^2 - x^2 - 3x = -3\sqrt{3x + x^2}$

$-3x = -3\sqrt{3x + x^2}$

$x = \sqrt{3x + x^2}$

$(x)^2 = [\sqrt{3x + x^2}]^2$

$x^2 = 3x + x^2$

$x^2 - x^2 = 3x$

$0 = 3x$

$0/3 = x$

$0 = x$

Is this right?
 
Last edited by a moderator:
Mathematics news on Phys.org
Yes, it's correct.
 
Good to know that I am right.
 

Similar threads