$1.$ You define a floating point variable float x $=1\mathrm{.}73$e$-27$;

You then define a second floating point variable:

float y $=$ x $*$ x;

That is $,$ y is storing x$-$squared. Does y contain the correct value for x$-$squared? If not, how would you declare variables x and y so that y does contain the correct value?