What is the vertex form of the quadratic y = 3x^2 + 18x - 4?

y = 3(x + 3)² - 31

Step-by-step explanation:

the equation of a parabola 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

take out a common factor of 3 from the first 2 terms

y = 3(x² + 6x) - 4

add/subtract ( half the coefficient of the x-term)² to x² + 6x

y = 3(x² + 2(3)x + 9 - 9 ) - 4

y = 3(x + 3)² - 27 - 4

y = 3(x + 3)² - 31 ← in vertex form

the median here is 25. your lowest value is 14 and highest value is 48. to find the third quartile, find the medium number in between 25 and 48 which would be 42 i believe.

more detail

step-by-step explanation: