Mathematical induction, proving inequation

• Nov 21st 2010, 05:18 AM
Nforce
Mathematical induction, proving inequation
We need to prove this with mathematical induction;

$
(1+x)^r \geq 1 + rx
$

r is natural number and $x \geq -1$

So if I insert r = 1 and x = -1

I get $0 \geq 0$

so it's true.

Then I insert r + 1, and I get

$(1+x)^{r+1} \geq 1 + x(r + 1)$
$(1+x)^{r+1} \geq 1 + xr + x$

What now? I just insert a value for x?
• Nov 21st 2010, 05:21 AM
Also sprach Zarathustra