Select one value from cubic equation

help
#1

Hello. I want to ask. How can I select the value of y2=1.1736 using octave? It should be y2=1.1736 not 1.7629

1655115294821614964467617970092
16551152948216149644676179700921920×864 43.4 KB

#2

Hi MUHAMMAD_SYAHID_ASHR, welcome to octave discourse.

You can use roots

# passing y2^3-2.234*y2^2+1.4627 = 0 to a vector with the power coeficients
ecuation = [1, -2.234, 0, 1.4627];
solutions = roots(ecuation)

sol =

1.7639
1.1756
-0.7054

#3

I got this. But, I have further calculation using y2=1.1756 (my picture stated wrong y2). How can I mention y2=1.1756?

#4

I didn’t understand your question. What is the problem with

y2 = solutions(2)
y2 =
1.1756

#5

y2 = 1.1756 does not satisfy 1.4893 < y2. Why do you want to use 1.1756 ?