Question

can someone use the graph of y=2x³+x²+x+8 to find d roots of y=2x³ +x²-x +5??.

Answer 1

I don't understand how looking at the graph of
y=2x³+x²+x+8 , which does not have a "nice" rational solution, will help you in solving
y = 2x^3 + x^2 - x + 5.
The latter also has an irrational solution.

http://www.wolframalpha.com/input/?i=y%3D2x%C2%B3%2Bx%C2%B2%2Bx%2B8

http://www.wolframalpha.com/input/?i=y%3D2x%C2%B3+%2Bx%C2%B2-x+%2B5

Are we suppose to notice that the two solutions are close ??