Suppose you used the first three nonzero terms of the power series representation to approximate

for

.

Obtain an upper bound on the error.

All the terms, are negative, I think? The parentheses confused me. So: power series representation is

The approximation is found, I think, just by plugging in x=1/2, for which I got 0.71875.

Then use the Taylor Inequality...

, so do I set M=1/384?

I stopped here because I wasn't sure if my value for M was right...I have the feeling it's not. Any help would be great.