The solution of
are 1 + 2i and 1 – 2i
<u>Solution:</u>
Given, equation is ![x^{2}-2 x+5=0](https://tex.z-dn.net/?f=x%5E%7B2%7D-2%20x%2B5%3D0)
We have to find the roots of the given quadratic equation
Now, let us use the quadratic formula
--- (1)
<em><u>Let us determine the nature of roots:</u></em>
Here in
a = 1 ; b = -2 ; c = 5
![b^2 - 4ac = 2^2 - 4(1)(5) = 4 - 20 = -16](https://tex.z-dn.net/?f=b%5E2%20-%204ac%20%3D%202%5E2%20-%204%281%29%285%29%20%3D%204%20-%2020%20%3D%20-16)
Since
, the roots obtained will be complex conjugates.
Now plug in values in eqn 1, we get,
![x=\frac{-(-2) \pm \sqrt{(-2)^{2}-4 \times 1 \times 5}}{2 \times 1}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-%28-2%29%20%5Cpm%20%5Csqrt%7B%28-2%29%5E%7B2%7D-4%20%5Ctimes%201%20%5Ctimes%205%7D%7D%7B2%20%5Ctimes%201%7D)
On solving we get,
![x=\frac{2 \pm \sqrt{4-20}}{2}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B2%20%5Cpm%20%5Csqrt%7B4-20%7D%7D%7B2%7D)
![x=\frac{2 \pm \sqrt{-16}}{2}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B2%20%5Cpm%20%5Csqrt%7B-16%7D%7D%7B2%7D)
![x=\frac{2 \pm \sqrt{16} \times \sqrt{-1}}{2}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B2%20%5Cpm%20%5Csqrt%7B16%7D%20%5Ctimes%20%5Csqrt%7B-1%7D%7D%7B2%7D)
we know that square root of -1 is "i" which is a complex number
![\begin{array}{l}{\mathrm{x}=\frac{2 \pm 4 i}{2}} \\\\ {\mathrm{x}=1 \pm 2 i}\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bl%7D%7B%5Cmathrm%7Bx%7D%3D%5Cfrac%7B2%20%5Cpm%204%20i%7D%7B2%7D%7D%20%5C%5C%5C%5C%20%7B%5Cmathrm%7Bx%7D%3D1%20%5Cpm%202%20i%7D%5Cend%7Barray%7D)
Hence, the roots of the given quadratic equation are 1 + 2i and 1 – 2i
I believe the appropriate volume is 160.
Answer: 0.16
Step-by-step explanation:
Given that the run times provided are normally distributed ;
Mean(x) of distribution = 3 hours 50 minutes
Standard deviation(s) = 30 minutes
The probability that a randomly selected runner has a time less than or equal to 3 hours 20 minutes
3 hours 20 minutes = (3 hrs 50 mins - 30 mins):
This is equivalent to :
[mean(x) - 1 standard deviation]
z 1 standard deviation within the mean = 0.84
z, 1 standard deviation outside the mean equals:
P(1 - z value , 1standard deviation within the mean)
1 - 0.8413 = 0.1587
= 0.16
Answer:
1=c
Step-by-step explanation:
1=c
2=d
3=e
4=a
5=b
I know 1 and 2 are correct, but I am not sure about the others
I'm not too sure how to explain this, sorry