Step OneUse the vertex to determine the basic equation for the parabola.
y = a(x - 2)^2 + 7 Notice the sign change for x. I have provided a graph to show how this would look with a = 1 (in red.)
What it means is the 2 has to be minus in order that the vertex will shift 2 units in the x direction.
Step TwoUse the point to solve for a.
y = a(x - 2)^2 + 7
When x = - 1
Then y = 3
3 = a(-1 - 2)^2 + 7 combine -1 with - 2
3 = a (-3)^2 + 7
3 = 9a + 7 Subtract 7 from both sides
3 - 7 = 9a
-4 = 9a Divide by 9.
a = -4/9
or
a = - 0.4444
y = -0.4444(x + 2)^2 + 7 <<<<<
answer
y = - 4/9 (x + 2)^2 + 7
Note: if you have choices, list them please.
Note: The red graph is y = (x - 2)^2 + 7 ; a = 1
The blue graph is y = - 4/9(x - 2)^2 + 7 ; a = - 0.44444
You should notice that the a does 3 things to the graph. Before you read the answer, what are those three things? The answer is in the comments.
Answer: B.
First, we have to have a question for this problem to create a solution. So, the example sentence is how many granola bars does each student get.
Second, an algebraic expression has a variable in it. So since we are trying to find the number of students, the variable is s.
From looking at C and D, we can already eliminate them. This question has mostly multiplication and division words in it, so it can't be addition and multiplication.
Now, we only have A and B left. A tip on how to figure this out is reading the word problem out thoroughly. I will use B as an example. 5 boxes of granola bars were multiplied by the number of granola bars each student got. From reading this, it makes more sense. But it does change the example sentence, though.
I hope this helped and this is the right answer!
Answer:
x + y
Step-by-step explanation:
Cups of pineapple juice = x
+Cups of cranberry juice = <u>y </u>
Total cups = x + y
Answer:
Eq: (x+a/2)²+(y+1)²=(a²-8)/4
Center: O(-a/2, -1)
Radius: r=0.5×sqrt(a²-8)
Mandatory: a>2×sqrt(2)
Step-by-step explanation:
The circle with center in O(xo,yo) and radius r has the equation:
(x-xo)²+(y-yo)²=r²
We have:
x²+y²+ax+2y+3=0
But: x²+ax=x²+2(a/2)x+a²/4-a²/4= (x+a/2)²-a²/4
And
y²+2y+3=y²+2y+1+2=(y+1)²+2
Replacing, we get:
(x+a/2)²-a²/4+(y+1)²+2=0
(x+a/2)²+(y+1)²=a²/4-2=(a²-8)/4
By visual inspection we note that:
- center of circle: O(-a/2, -1)
- radius: r=sqrt((a²-8)/4)=0.5×sqrt(a²-8). This means a²>8 or a>2×sqrt(2)
Answer:
x < 3 and x > -1
Step-by-step explanation:
Step 1: Subtract 2 from both sides.
Step 2: Solve absolute value.
- We know x - 1 < 2 and x - 1 > -2.
Condition 1:
Condition 2:
Therefore, the answer is x < 3 and x > -1.