Well, you know that x^3 does not intersect any straight line in more than one place, but it's not factorable.
So, what numeric techniques have you learned? False position, Newton's method, bisection?
Just looking at a graph probably won't get you to three places unless you zoom in a few times, as at
http://www.wolframalpha.com/input/?i=x^3+-%28+3x-3%29+for+-2.104+%3C%3D+x+%3C%3D+-2.103
Find all solutions of the equation correct to three decimal places. (ex: 0.617 or -1.764)
x^3=3x-3
2 answers
What method are you using to solve a cubic,
since there is no simple "formula" method ?
your two answers do not satisfy the equation
here is what Wolfram has
http://www.wolframalpha.com/input/?i=solve+x%5E3-3x%2B3%3D0
click on "approximate forms" to see one real solution
x = appr -2.1038
and two imaginary roots.
since there is no simple "formula" method ?
your two answers do not satisfy the equation
here is what Wolfram has
http://www.wolframalpha.com/input/?i=solve+x%5E3-3x%2B3%3D0
click on "approximate forms" to see one real solution
x = appr -2.1038
and two imaginary roots.
1 answer