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33 votes
Y= - x^2 + 4x + 6 in vertex form

User The Dark
by
2.7k points

2 Answers

16 votes
16 votes

Answer:

y = - (x - 2)² + 10

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

y = - x² + 4x + 6 ( factor out - 1 from the first 2 terms )

y = - (x² - 4x) + 6

To complete the square

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

y = - (x² + 2(- 2) + 4 - 4) + 6

y = - (x - 2)² + 4 + 6

y = - (x - 2)² + 10 ← in vertex form

User Jordan Gray
by
3.4k points
9 votes
9 votes

HI THERE!


\rm \color{lime}(2,10)

step-by-step Step-by-step explanation:


\rm \color{lime}y = - {x}^(2) + 4x + 6

  • identify the coefficients


\rm \color{lime}a = - 1,b = 4

  • substitute the coefficient into the expression
  • find the x-coordinate of the vertex by substituting a = - 1 and b=4

  • \tt \tiny \: x = - (b)/(29)


\rm \color{lime}x = - (4)/(2x( - 1))

  • solve the equation for X
  • find the y-coordinate of the vertex by evaluating the function for x = 2


\rm \color{lime}y = - {x}^(2) + 4x + 6,x = 2

  • calculate the function value for x = 2


\rm \color{lime}y = 10

  • since the value of the function is 10 for x = 2 the vertex of the graph of the quadratic function is a (2,10)


= \rm \color{hotpink} (2,10)

hope it helps

User Navid Khan
by
2.5k points