$\displaystyle y=x-x^5$

find the slope of the tangent line to the curve at point (1,0)

slope =

$\displaystyle

\frac{f(x)-f(a)}{x-a}

$

I'm a little confused on what 'a' equals, but going off my notes im gonna say its 1, being x value in the point

$\displaystyle

\frac{(x-x^5)-(1-1^5)}{x-1}

$

=

$\displaystyle

\frac{x-x^5}{x-1}

$

and thats where I get stuck