Y1 is the simplest parabola. Its vertex is at (0,0) and it passes thru (2,4). This is enough info to conclude that y1 = x^2.
y4, the lower red graph, is a bit more of a challenge. We can easily identify its vertex, which is (-4,0), and several points on the grah, such as (2,-3).
Let's try this: assume that the general equation for a parabola is
y-k = a(x-h)^2, where (h,k) is the vertex. Subst. the known values,
-3-(-4) = a(2-0)^2. Then 1 = a(2)^2, or 1 = 4a, or a = 1/4.
The equation of parabola y4 is y+4 = (1/4)x^2
Or you could elim. the fraction and write the eqn as 4y+16=x^2, or
4y = x^2-16, or y = (1/4)x - 4. Take your pick! Hope this helps you find "a" for the other parabolas.
Answer:
32, percentage increaced by 25% =40
Step-by-step explanation:
Answer:
y =2x+9
Step-by-step explanation:
-2x+y=9
Add 2x to each side
-2x+2x+y=2x+9
y =2x+9
It could be seen from the table that when x is 2, the y value is 0. Thus, it can be concluded that the x intercept is (2,0)
The correct answer is B
Example: <span>the second step in the process for factoring the trinomial x^2-3x-40 is to:</span> <span>Well you really should find the sum of the factors of −40 (not 40) </span>
<span>But before you can do that, you need to LIST the factors of −40 (not 40) </span>
<span>−1 * 40 </span>
<span>−2 * 20 </span>
<span>−4 * 10 </span>
<span>−5 * 8 </span>
<span>−8 * 5 </span>
<span>−10 * 4 </span>
<span>−20 * 2 </span>
<span>−40 * 1 </span>
<span>NOW we find the sum of the factors of −40 </span>
<span>−1 + 40 = 39 </span>
<span>−2 + 20 = 18 </span>
<span>−4 + 10 = 6 </span>
<span>−5 + 8 = 3 </span>
<span>−8 + 5 = −3 </span>
<span>−10 + 4 = −6 </span>
<span>−20 + 2 = −18 </span>
<span>−40 + 1 = −39 </span>
<span>Then we choose the factors of −40 whose sum is −3 ---> −8 and 5 </span>
<span>x^2 − 3x − 40 = (x − 8) (x + 5) </span>
<span>So FIRST step is B, SECOND step is C, and final step is factoring. </span>
What Rita did was combine these 2 steps together, which you will learn to do as you get better at factoring.
