Plot[ (x-1)^5, {x,0.9999,1.0001} ]

Expand[ (x-1)^5 ]

Plot[ x^5 - 5x^4 +10x^3 -10x^2 +5x -1 , {x, 0.999,1.001}]

Plot[ x Exp[x], {x, -10,2} ]

f[x_] = x Exp[x]

Plot[ f[x] , {x, -9,2} ]

Solve[ f[x] == 0, x ]

g[x_] = D[ f[x], x ]

Plot[ g[x],{x, -10,2}]

Solve[ g[x] == 0, x ]

D[ D [f[x], x],x]

N [ Integrate[  Exp[x^2], {x, -2, 4} ]  ]

N[

N[%27]

?Erfi