Use Euler's method with step size $10^{-n}$ for $n=1,2,3,4.$ to estimate $x(1)$, where $f(x)$ is the solution of the initial-value problem below.
$x'=f(x)=-x$
$x(0)=1$
EDIT / UPDATE:
x_n+1=x_n + f(x_n)h
how does it become x_n+1= x_n[(1-h)^(n+1)]
Solution then is X(1)=X_n where n=[1/h]