數學題: ( 急 Find the turning points and inflexion points of the following functions?

y=x^3-3x+1.....(1)
y=x^6-3(x^2).....(2)

1.
y=x^3-3x+1
y'=3x^2-3=3(x+1)(x-1)
y''=6x
turning points: when y'=0, x=1 or -1, (1, -1), (-1, 3)
inflecion points: when y''=0, x=0, (0,1)


2.
y=x^6-3x^2=x^2(x^4-3) (1/a^2)(1/a^4-3)
y'=6x^5-6x=6x(x^4-1)=6(x-1)(x+1)(x^2+1)
y''=30x^4-6=6(5x^4-1)=6(ax-1)(ax+1)(a^2x^2+1) .....a=5^(1/4)
turning points: when y'=0, x=1 or -1, (1, -2), (-1, -2)
inflecion points: when y''=0, x=(1/5)^(1/4) or -(1/5)^(1/4) , (1/a,-2.8/√5), (-1/a,-2.8/√5)