What is the y-coordinate of the vertex of the parabola?
f(x)= -x^2 - 2x +6

  7

Step-by-step explanation:

The function can be written in vertex form as ...

  f(x) = -(x +1)^2 +7

The vertex is then identifiable as (-1, 7). The y-coordinate is 7.

_____

Vertex form is ...

  f(x) = a(x -h)^2 +k

where "a" is the vertical scale factor, and (h, k) is the vertex point. It is convenient to arrive at this form by factoring "a" from the first two terms, then adding and subtracting the square of the remaining x-coefficient inside and outside parentheses.

  f(x) = -(x^2 +2x) +6

  f(x) = -(x^2 +2x +1) + 6 -(-1) . . . . completing the square

  f(x) = -(x +1)^2 +7 . . . . . . . . . . . . vertex form; a=-1, (h, k) = (-1, 7)

answer: dead jah

step-by-step explanation:

bullet + jah= dead jah

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional