Use the 3rd degree polynomial for e^x to estimate sqrt of e (4 decimal places). Find, and justify, an upper bound in error.

I know what e^x is as an expansion.

I know to go up to the 3rd degree, fine. To estimate the square root of e, would I just plug in 1 into the equation and then take the square root of the sum of the numbers? For the upper bound I know to use taylor's remained theorem