Rewrite the quadratic function in vertex form.
y=3x^2-12x+4

y = 3(x - 2)² - 8

Step-by-step explanation:

The equation of a quadratic in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

To obtain this form use the method of completing the square

• The coefficient of the x² term must be 1

Factor out 3 from the first 2 terms

y = 3(x² - 4x ) + 4

• add/subtract (half the coefficient of the x- term )² to x² - 4x

y = 3(x² + 2(- 2)x + (- 2)² - (- 2)² ) + 4 ← complete the square

y = 3(x - 2)² - 12 + 4

y = 3(x - 2)² - 8 ← in vertex form

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step-by-step explanation: