Maxima

May answer key po ba kayo nito. Icheck ko lang po sana kung tama answers ko. Thank you po. Critical points/maxima and minima

y=4-6x+x²
y=(2x-1)²
y=2+12x-x³
y=x³-3x²-9x+20
y=x³-3x²+4x+5
y=x³-6x²+12x
y=x⁴+2x²+8x+3
y=16x+4x²-x⁴
y=x²(x-2)²
a³y=x⁴
9a³y=x(4a-x)³
a³y=x²(2a²-x²)
a³y=x³(4a-3x)
a⁵y=x⁴(3a²-2x²)