y=-8x²+12x 怎么配方?

y=-8x²+12x 怎么配方?
y=-8x²+12x 怎么配方?

y=-8x²+12x 怎么配方?
y=-8x²+12x
=－8﹙x²－3／2x﹚
=－8﹙x²－2×x×¾＋9／16﹚＋8×9／16
=－8﹙x－¾﹚²＋4.5

y=8(x^2+3/2x)
=8[(x^2+3/2x+9/16)-9/16]
=8(x+3/4)^2-9/2