x=-4 doesn't work, you'd get 5 = -3, which obviously isn't true. That is because according to your geometrical construction, it wouldn't make sense for x to be negative, that wouldn't create any kind of triangle if it was the case.
@singularityfnКүн бұрын
Squaring created an extra root
@Jan_Lei.Күн бұрын
for x=-4 i get: 5 = -3 and that seems to be not real 😉
@PrypakКүн бұрын
@Jan_Lei. Well you have 12/x that gives you -3, to which you subtract -4, so you add 4 and it's √7, I don't really know how you get your 5 from there on
@PrypakКүн бұрын
@@singularityfn exactly, but my point is that you can disregard -4 right away because the way the AI voice's put it is using geometry, and if we were to allow the sides to have a negative length, it'd be going the opposite way, and you wouldn't have any triangle
@theosmit6366Күн бұрын
@Prypak 12/-4 = -3; -3 - (-4) = 1. Sqrt(1) = 1
@SUICR7AF2 күн бұрын
If x=-4, the right side is less than 0 while the left is more or equal 0
@ZomsteveКүн бұрын
You're right but in algebraic terms, both values are acceptable He only used geometry to simplify the problem
@JamesMcCullough-lu9gf17 сағат бұрын
@Zomsteve Geometry is somewhat based off of algebra. Anything you do in geometry will be acceptable in algebraic terms, and the root -4 is not acceptable because literally checking it with the original equation proves that it is extraneous. Therefore, only 3 is acceptable.
@princianorvz5 сағат бұрын
No need for a solution, 3 is one correct answer.
@Malekthebirb21 сағат бұрын
Great way to solve the equation without having to go through an annoying quartic! You probably do know this already but -4 is an extraneous solution it would be great if you included that in the video. Much love
@brain_station_videos20 сағат бұрын
Thanks, you're right. I should've addressed that.
@AnotherOne-s8vКүн бұрын
You need to check the roots of x. If x = 3: sqrt(12/3 - 3) + sqrt(12 - 3) = 12/3 sqrt(1) + sqrt(9) = 4 1 + 3 = 4 which is correct If x = -4: sqrt(-(12/4) + 4) + sqrt(12 + 4) = - (12/4) sqrt(1) + sqrt(16) = -3 1 + 4 = -3 which is incorrect
@musicsubicandcebu177421 сағат бұрын
One root can be found easily by noting that (12/x) - x must be greater than, or equal to, 0 Solving the inequality gives x = 1, 2 or 3. Checking each in turn makes x = 3 a winner.