So I was doing some Vector Calculus homework and was working with Lagrange Multipliers, but then I came across a polynomial that I either forgot how to factor or never learned. I plugged it into Wolfram and was able to get the real solution, and finished the problem, but I'd like to know if there is a simple way to factor this out and if so what is it?
$3y^3 +y -4 = 0$
I know the real solution to this is $y=1$, but could someone give me a step by step process to receive this answer in the simplest way they know?
Edit: I'm sorry if I didn't make this clear. I Actually didn't know before hand $y=1$ this came after I looked for the solution on wolfram alpha. What I am looking for is actually how to factor that polynomial with no given information of the roots.