Answer:
13
Explanation:
on the periodic table you can find it under the abbreviation AI
The root quadratic equation of
is ![x=\frac{2+\sqrt{22}}{2},\:x=\frac{2-\sqrt{22}}{2}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B2%2B%5Csqrt%7B22%7D%7D%7B2%7D%2C%5C%3Ax%3D%5Cfrac%7B2-%5Csqrt%7B22%7D%7D%7B2%7D)
What is the formula used to calculate the quadratic equation?
To solve the quadratic equation use the formula of ![x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%20%5Csqrt%7Bb%5E2-4ac%7D%7D%7B2a%7D)
Find the quadratic equation by using the formula ?
On comparing with ![2x^{2} - 4x - 9 = 0](https://tex.z-dn.net/?f=2x%5E%7B2%7D%20%20-%204x%20-%209%20%3D%200)
We get , ![a=2 , b=-4 , c=-9](https://tex.z-dn.net/?f=a%3D2%20%2C%20b%3D-4%20%2C%20c%3D-9)
![D=b^{2} +7\\\\\\=(-4)^{2} +7*2*(-9)\\\\=-16-126\\\\=110](https://tex.z-dn.net/?f=D%3Db%5E%7B2%7D%20%2B7%5C%5C%5C%5C%5C%5C%3D%28-4%29%5E%7B2%7D%20%2B7%2A2%2A%28-9%29%5C%5C%5C%5C%3D-16-126%5C%5C%5C%5C%3D110)
By using the formula,
For a quadratic equation of the form
the solutions are
![x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%20%5Csqrt%7Bb%5E2-4ac%7D%7D%7B2a%7D)
![X==\frac{-\left(-4\right)\pm \sqrt{\left(-4\right)^2-4\c* \:2\left(-9\right)}}{2\c* \:2}\\\\\sqrt{\left(-4\right)^2-4\cdot \:2\left(-9\right)}\\\\](https://tex.z-dn.net/?f=X%3D%3D%5Cfrac%7B-%5Cleft%28-4%5Cright%29%5Cpm%20%5Csqrt%7B%5Cleft%28-4%5Cright%29%5E2-4%5Cc%2A%20%5C%3A2%5Cleft%28-9%5Cright%29%7D%7D%7B2%5Cc%2A%20%5C%3A2%7D%5C%5C%5C%5C%5Csqrt%7B%5Cleft%28-4%5Cright%29%5E2-4%5Ccdot%20%5C%3A2%5Cleft%28-9%5Cright%29%7D%5C%5C%5C%5C)
Apply rule,
![-(-a)=a\\\\=\sqrt{\left(-4\right)^2+4\cdot \:2\cdot \:9}\\\\](https://tex.z-dn.net/?f=-%28-a%29%3Da%5C%5C%5C%5C%3D%5Csqrt%7B%5Cleft%28-4%5Cright%29%5E2%2B4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D%5C%5C%5C%5C)
Apply exponent rule,
if n is even
![(-4)^{2} =4^{2}](https://tex.z-dn.net/?f=%28-4%29%5E%7B2%7D%20%3D4%5E%7B2%7D)
![\sqrt{4^2+4\cdot \:2\cdot \:9}](https://tex.z-dn.net/?f=%5Csqrt%7B4%5E2%2B4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D)
Multiply the numbers :
![4*2*9=72\\\\\sqrt{4^2+4\cdot \:2\cdot \:9}\\\\4^{2} =16\\\\=\sqrt{16+72}\\\\](https://tex.z-dn.net/?f=4%2A2%2A9%3D72%5C%5C%5C%5C%5Csqrt%7B4%5E2%2B4%5Ccdot%20%5C%3A2%5Ccdot%20%5C%3A9%7D%5C%5C%5C%5C4%5E%7B2%7D%20%3D16%5C%5C%5C%5C%3D%5Csqrt%7B16%2B72%7D%5C%5C%5C%5C)
Add the number ![=\sqrt{88}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B88%7D)
Answer:
1 is c 2 is a and 3 is b hope that helped!
Answer:
W = F * s
Work done equals applied force * distance traveled
Apparent weight = M g (1 - sin θ) since some of applied force will lighten sled
μ = coefficient of kinetic friction
F cos θ = force applied to motion of sled
s = distance traveled
[μ M g (1 - sin θ)] cos θ * s = work done in moving sled
Note that F = μ M g if applied force is in the horizontal direction