Answer:
789
Step-by-step explanation:
8679/789 = 11
Answer:
![\large\boxed{y=\dfrac{1}{4}x^2-x-4}](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7By%3D%5Cdfrac%7B1%7D%7B4%7Dx%5E2-x-4%7D)
Step-by-step explanation:
The equation of a parabola in vertex form:
![y=a(x-h)^2+k](https://tex.z-dn.net/?f=y%3Da%28x-h%29%5E2%2Bk)
<em>(h, k)</em><em> - vertex</em>
The focus is
![\left(h,\ k+\dfrac{1}{4a}\right)](https://tex.z-dn.net/?f=%5Cleft%28h%2C%5C%20k%2B%5Cdfrac%7B1%7D%7B4a%7D%5Cright%29)
We have the vertex (2, -5) and the focus (2, -4).
Calculate the value of <em>a</em> using ![k+\dfrac{1}{4a}](https://tex.z-dn.net/?f=k%2B%5Cdfrac%7B1%7D%7B4a%7D)
<em>k = -5</em>
<em>add 5 to both sides</em>
<em>multiply both sides by 4</em>
![4\!\!\!\!\diagup^1\cdot\dfrac{1}{4\!\!\!\!\diagup_1a}=4](https://tex.z-dn.net/?f=4%5C%21%5C%21%5C%21%5C%21%5Cdiagup%5E1%5Ccdot%5Cdfrac%7B1%7D%7B4%5C%21%5C%21%5C%21%5C%21%5Cdiagup_1a%7D%3D4)
![\dfrac{1}{a}=4\to a=\dfrac{1}{4}](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7Ba%7D%3D4%5Cto%20a%3D%5Cdfrac%7B1%7D%7B4%7D)
Substitute
![a=\dfrac{1}{4},\ h=2,\ k=-5](https://tex.z-dn.net/?f=a%3D%5Cdfrac%7B1%7D%7B4%7D%2C%5C%20h%3D2%2C%5C%20k%3D-5)
to the vertex form of an equation of a parabola:
![y=\dfrac{1}{4}(x-2)^2-5](https://tex.z-dn.net/?f=y%3D%5Cdfrac%7B1%7D%7B4%7D%28x-2%29%5E2-5)
The standard form:
![y=ax^2+bx+c](https://tex.z-dn.net/?f=y%3Dax%5E2%2Bbx%2Bc)
Convert using
![(a-b)^2=a^2-2ab+b^2](https://tex.z-dn.net/?f=%28a-b%29%5E2%3Da%5E2-2ab%2Bb%5E2)
![y=\dfrac{1}{4}(x^2-2(x)(2)+2^2)-5\\\\y=\dfrac{1}{4}(x^2-4x+4)-5](https://tex.z-dn.net/?f=y%3D%5Cdfrac%7B1%7D%7B4%7D%28x%5E2-2%28x%29%282%29%2B2%5E2%29-5%5C%5C%5C%5Cy%3D%5Cdfrac%7B1%7D%7B4%7D%28x%5E2-4x%2B4%29-5)
<em>use the distributive property: a(b+c)=ab+ac</em>
![y=\left(\dfrac{1}{4}\right)(x^2)+\left(\dfrac{1}{4}\right)(-4x)+\left(\dfrac{1}{4}\right)(4)-5\\\\y=\dfrac{1}{4}x^2-x+1-5\\\\y=\dfrac{1}{4}x^2-x-4](https://tex.z-dn.net/?f=y%3D%5Cleft%28%5Cdfrac%7B1%7D%7B4%7D%5Cright%29%28x%5E2%29%2B%5Cleft%28%5Cdfrac%7B1%7D%7B4%7D%5Cright%29%28-4x%29%2B%5Cleft%28%5Cdfrac%7B1%7D%7B4%7D%5Cright%29%284%29-5%5C%5C%5C%5Cy%3D%5Cdfrac%7B1%7D%7B4%7Dx%5E2-x%2B1-5%5C%5C%5C%5Cy%3D%5Cdfrac%7B1%7D%7B4%7Dx%5E2-x-4)
Consider the function
First, factor it:
![G(x) = -2x^3 - 15x^2 + 36x=-x(2x^2+15x-36)=\\ \\=-x\cdot 2\cdot \left(x-\dfrac{-15-\sqrt{513}}{4}\right)\cdot \left(x-\dfrac{-15+\sqrt{513}}{4}\right).](https://tex.z-dn.net/?f=G%28x%29%20%3D%20-2x%5E3%20-%2015x%5E2%20%2B%2036x%3D-x%282x%5E2%2B15x-36%29%3D%5C%5C%20%5C%5C%3D-x%5Ccdot%202%5Ccdot%20%5Cleft%28x-%5Cdfrac%7B-15-%5Csqrt%7B513%7D%7D%7B4%7D%5Cright%29%5Ccdot%20%5Cleft%28x-%5Cdfrac%7B-15%2B%5Csqrt%7B513%7D%7D%7B4%7D%5Cright%29.)
The x-intercepts are at points ![\left(\dfrac{-15-\sqrt{513} }{4},0\right),\ (0,0),\ \left(\dfrac{-15+\sqrt{513} }{4},0\right).](https://tex.z-dn.net/?f=%5Cleft%28%5Cdfrac%7B-15-%5Csqrt%7B513%7D%20%7D%7B4%7D%2C0%5Cright%29%2C%5C%20%280%2C0%29%2C%5C%20%5Cleft%28%5Cdfrac%7B-15%2B%5Csqrt%7B513%7D%20%7D%7B4%7D%2C0%5Cright%29.)
1. From the attached graph you can see that
- function is positive for
![x\in \left(-\infrty, \dfrac{-15-\sqrt{513} }{4}\right)\cup \left(0,\dfrac{-15+\sqrt{513} }{4}\right);](https://tex.z-dn.net/?f=x%5Cin%20%5Cleft%28-%5Cinfrty%2C%20%5Cdfrac%7B-15-%5Csqrt%7B513%7D%20%7D%7B4%7D%5Cright%29%5Ccup%20%5Cleft%280%2C%5Cdfrac%7B-15%2B%5Csqrt%7B513%7D%20%7D%7B4%7D%5Cright%29%3B)
- function is negative for
![x\in \left(\dfrac{-15-\sqrt{513} }{4},0\right)\cup \left(\dfrac{-15+\sqrt{513} }{4},\infty\right).](https://tex.z-dn.net/?f=x%5Cin%20%5Cleft%28%5Cdfrac%7B-15-%5Csqrt%7B513%7D%20%7D%7B4%7D%2C0%5Cright%29%5Ccup%20%5Cleft%28%5Cdfrac%7B-15%2B%5Csqrt%7B513%7D%20%7D%7B4%7D%2C%5Cinfty%5Cright%29.)
2. Since
the function is neither even nor odd.
3. The domain is
the range is
To get percent error you take actual-predicted and divide by the actual then multiply by 100 to get the percent.
65-50=15
15/60=0.25
0.25 times 100 =25%