Hi, got a question i'm a bit stuck with,

Plot the graph of y=e^-2x
Use the graph to find the gradient at x=0 (which i work out from the graph to be 1.8125). Does this sound correct and is there a way to work the gradient out by calculation to check my answer?

Also i'm asked to find the value of x when y=0.5 by calculation.
0.5=e^-2x
loge0.5=loge^-2x
loge0.5=x -2loge
loge0.5=x(x)-2
ln0.5=-2
ln0.5/-2= 0.35(2d.p) Does this seem right?

Any help appreciated. THnks