with(stats): with(plots):

N:=(x,m,sig) -> statevalf[cdf, normald[m,sqrt(sig)]](x):
B:=(n,p,k)->(n!*(p^k)*(1-p)^(n-k))/(k!*(n-k)!):
P:=(m,k)->((m^k*exp(-m))/k!):
y:=(a,b)->1/(b-a):
UNI:=(a,b)->plot([[a-sqrt(b^2),0], [a,0],[ a,y(a,b)],[ b,y(a,b)], [b,0], [b+sqrt(a^2),0]], 
style=line):
g:=(x,m,v)->(exp(-(x-m)^2/(2*v)))/sqrt(2*Pi*v):
phi:=(z)->exp(-(z^2)/2)/sqrt(2*Pi):