一般式 頂點式[form.4]{part 2}

y = 3x² – 6x – 2
y = 3 (x² – 2x) – 2
y = 3 [ (x – 1) – 1] – 2
y = 3(x-1) – 3 – 2
y = 3(x-1) – 5

y = 5x² – 15x – 2
y = 5(x² – 3x) – 2
y = 5[(x – 1.5) – 2.25] – 2
y = 5(x – 1.5) – 11.25 – 2
y = 5(x – 1.5) – 13.25

y = 2x² + 5x + 1
y = 2 (x² + 2.5x) + 1
y = 2[(x + 1.25) – 1.5625] + 1
y = 2(x + 1.25) – 3.125 + 1
y = 2(x + 1.25) – 2.125


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