Question 1189334


Given {{{f(x)=3x^4 -2x^3 + 7x -2}}},
..........signs: +     -      +   -

 how many sign changes are there in the coefficient of {{{f(-x)}}}?

{{{f(-x)=3(-x)^4 -2(-x)^3 + 7(-x) -2}}}
{{{f(-x)=3x^4 +2x^3 - 7x -2}}} 
..........signs:+     +     -   -   => compare to {{{f(x)}}} and you see that second sign changes from - to +, third sign changes from + to -

so, {{{two}}} sign changes are there