Answer:
0.9375
Step-by-step explanation:
Given the following :
Number of coin tosses = 7
Probability that number of heads obtained will be between 2 and 7 inclusive?
x = 2,3,4,5,6,7
Probability (P) = number of required outcomes / total possible outcomes
For a coin toss = 1 Head (H), 1 tail (T)
P(H) = 1 / 2
P(X) = C(7,x) * (1/2)^7
P(X) = C(7, x) / 0.5^-7
P(X) = [C(7,2) + C(7, 3)+ C(7,4) +C(7,5) + C(7,6) +C(7,7)] / 128
P(X) = (21 + 35 + 35 + 21 + 7 + 1) / 128
P(X) = 120 / 128
P(X) = 0.9375
When we are given 3 sides, we try to solve the angles first by using the
law of cosines
cos (A) = [b^2 + c^2 - a^2] / (2 * b * c)
cos (A) = [43^2 + 17^2 -27^2] / (2 * 43 * 17)
cos (A) = [1,849 + 289 -729] /
<span>
<span>
<span>
1,462
</span></span></span>cos (A) = 1,409 / 1,462
cos (A) =
<span>
<span>
<span>
0.96374829001368
Angle A = 15.475
Now that we have one angle, we next can use the
Law of Sines
sin(B) / side b = sin(A) / side a
sin(B) = sin(A) * sideb / sidea
</span></span></span><span>sin(B) = sin(15.475) * 43 / 27
</span><span>sin(B) = 0.26682 * 43 / 27
sin (B) = </span><span>0.424935555555</span>
Angle B = 25.147 Degrees
Remember the arc sine (<span>0.424935555555) also equals </span>
<span>
<span>
<span>
154.85
</span></span></span>Finally, calculating the third angle is quite easy
Angle C = 180 - Angle (A) - Angle(B)
Angle C = 180 - 15.475 - 154.85
Angle C = 9.675
Source:
http://www.1728.org/trigtut2.htm
Given:
cos 120°
To find:
The exact value of cos 120° in simplest form with a rational denominator.
Solution:
We have,
It can be written as
![[\because \cos (90^\circ-\theta)=-\sin \theta]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Ccos%20%2890%5E%5Ccirc-%5Ctheta%29%3D-%5Csin%20%5Ctheta%5D)
![[\because \sin 30^\circ=\dfrac{1}{2}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%2030%5E%5Ccirc%3D%5Cdfrac%7B1%7D%7B2%7D%5D)
Therefore, the exact value of cos 120° is 
.
Step-by-step explanation:
Only 1 number works. 1 will make 819 which is divisible by 9.
Since it is 1 of ten numbers can go in the blank, the answer is 1/10 which is 0.1
The 10 number choices are
0,1,2,3,4,5,6,7,8,9
The only one that works is 1 as I've stated.
