Given an interval $[a,b]$ that satisfies hypothesis of Rolle's theorem for function $f(x) = x^4 + x^3 - x^2 + x -2$
If $a = -2$, how do I find $b$ ?
This is what Ive done so far, Not sure if it is right...
Rolles theorem says if $f(a)=f(b)$ at some point in the interval $[a,b]$ the derivative of the function is zero.
so,$f(a)=32-8-8-4=12$
Lets find a $b$ where $f(b)=12$
so, $f(b)=b^4+b^3-b^2+b-2=12$
This is hard to do, but wolfram alpha says $b=1.77$
So somewhere between $-2$ and $1.77$ the derivative is zero.