# proof using IVT

• October 28th 2010, 05:38 PM
zebra2147
proof using IVT
My professor assigned this exercise and I'm not really sure how to get it started.

Suppose $f(a,b)<0$ and $f(c,d)>0$. Let $\phi : [0,1]\rightarrow R^2$ be determined by $\phi (t)=(1-t)(a,b)+t(c,d)$. Apply Bolzano's Intermediate Value Theorem to $g=f(\phi )$.

Any guidance would be appreciated.
• October 28th 2010, 08:35 PM
Drexel28
Guidance with what...is there a question here?
• October 31st 2010, 08:20 AM
zebra2147
I'm not sure how to use the Intermediate Value Theorem to $g=f(\phi )$.