Answer:
cos(a + b) = ![\frac{1}{12}(1-2\sqrt{30})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12%7D%281-2%5Csqrt%7B30%7D%29)
Step-by-step explanation:
cos(a + b) = cos(a).cos(b) - sin(a).sin(b) [Identity]
cos(a) = ![-\frac{1}{3}](https://tex.z-dn.net/?f=-%5Cfrac%7B1%7D%7B3%7D)
cos(b) = ![-\frac{1}{4}](https://tex.z-dn.net/?f=-%5Cfrac%7B1%7D%7B4%7D)
Since, terminal side of angle 'a' lies in quadrant 3, sine of angle 'a' will be negative.
sin(a) =
[Since, sin(a) =
]
= ![-\sqrt{\frac{8}{9}}](https://tex.z-dn.net/?f=-%5Csqrt%7B%5Cfrac%7B8%7D%7B9%7D%7D)
= ![-\frac{2\sqrt{2}}{3}](https://tex.z-dn.net/?f=-%5Cfrac%7B2%5Csqrt%7B2%7D%7D%7B3%7D)
Similarly, terminal side of angle 'b' lies in quadrant 2, sine of angle 'b' will be negative.
sin(b) =
= ![-\sqrt{\frac{15}{16}}](https://tex.z-dn.net/?f=-%5Csqrt%7B%5Cfrac%7B15%7D%7B16%7D%7D)
= ![-\frac{\sqrt{15}}{4}](https://tex.z-dn.net/?f=-%5Cfrac%7B%5Csqrt%7B15%7D%7D%7B4%7D)
By substituting these values in the identity,
cos(a + b) = ![(-\frac{1}{3})(-\frac{1}{4})-(-\frac{2\sqrt{2}}{3})(-\frac{\sqrt{15}}{4})](https://tex.z-dn.net/?f=%28-%5Cfrac%7B1%7D%7B3%7D%29%28-%5Cfrac%7B1%7D%7B4%7D%29-%28-%5Cfrac%7B2%5Csqrt%7B2%7D%7D%7B3%7D%29%28-%5Cfrac%7B%5Csqrt%7B15%7D%7D%7B4%7D%29)
= ![\frac{1}{12}-\frac{\sqrt{120}}{12}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12%7D-%5Cfrac%7B%5Csqrt%7B120%7D%7D%7B12%7D)
= ![\frac{1}{12}(1-\sqrt{120})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12%7D%281-%5Csqrt%7B120%7D%29)
= ![\frac{1}{12}(1-2\sqrt{30})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12%7D%281-2%5Csqrt%7B30%7D%29)
Therefore, cos(a + b) = ![\frac{1}{12}(1-2\sqrt{30})](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B12%7D%281-2%5Csqrt%7B30%7D%29)
30/40 say no, so x/1000 would say no. 1000/40=25, 25*30=750. So, about 750 would dislike it.
Answer: 20 feet perimeter is the largest allowed
Step-by-step explanation: width=2.5 length=no more than 3x2.5
so find longest possible length allowed...
2.5x3=7.5
calculate largest perimeter allowed...
2(7.5+2.5)=20
If the point P(x, y) partitions the segment AB in the ratio 1 : 1, then the point P is midpoint of segment AB.
The formula of a midpoint of segment:
![A(x_A;\ y_A),\ B(x_B,\ y_B)\\\\P_{AB}\left(\dfrac{x_A+x_B}{2};\ \dfrac{y_A+y_B}{2}\right)](https://tex.z-dn.net/?f=A%28x_A%3B%5C%20y_A%29%2C%5C%20B%28x_B%2C%5C%20y_B%29%5C%5C%5C%5CP_%7BAB%7D%5Cleft%28%5Cdfrac%7Bx_A%2Bx_B%7D%7B2%7D%3B%5C%20%5Cdfrac%7By_A%2By_B%7D%7B2%7D%5Cright%29)
We have:
![A(13,\ 1)\to x_A=13,\ y_A=1\\B(-5,\ -3)\to x_B=-5,\ y_B-3\\\\P\left(\dfrac{13+(-5)}{2};\ \dfrac{1+(-3)}{2}\right)\to P\left(\dfrac{8}{2};\ \dfrac{-2}{2}\right)\to P(4,\ -1)](https://tex.z-dn.net/?f=A%2813%2C%5C%201%29%5Cto%20x_A%3D13%2C%5C%20y_A%3D1%5C%5CB%28-5%2C%5C%20-3%29%5Cto%20x_B%3D-5%2C%5C%20y_B-3%5C%5C%5C%5CP%5Cleft%28%5Cdfrac%7B13%2B%28-5%29%7D%7B2%7D%3B%5C%20%5Cdfrac%7B1%2B%28-3%29%7D%7B2%7D%5Cright%29%5Cto%20P%5Cleft%28%5Cdfrac%7B8%7D%7B2%7D%3B%5C%20%5Cdfrac%7B-2%7D%7B2%7D%5Cright%29%5Cto%20P%284%2C%5C%20-1%29)
Answer: C. (4, -1)
Answer: Our required probability is 0.39.
Step-by-step explanation:
Since we have given that
X be the exponentially distributed with mean life = 6 years
So, E[x]=6
![\dfrac{1}{\lambda}=6\\\\\lambda=\dfrac{1}{6}](https://tex.z-dn.net/?f=%5Cdfrac%7B1%7D%7B%5Clambda%7D%3D6%5C%5C%5C%5C%5Clambda%3D%5Cdfrac%7B1%7D%7B6%7D)
So, our cumulative distribution function would be
![F(x)=1-e^{-\lambda x}](https://tex.z-dn.net/?f=F%28x%29%3D1-e%5E%7B-%5Clambda%20x%7D)
We need to find the probability that the CPU fails within 3 years.
![P(X](https://tex.z-dn.net/?f=P%28X%3C3%29%3DF%283%29%3D1-e%5E%7B-%5Cfrac%7B1%7D%7B6%7D%5Ctimes%203%7D%5C%5C%5C%5C%3D1-e%5E%7B-%5Cfrac%7B1%7D%7B2%7D%7D%5C%5C%5C%5C%5Capprox%200.39)
Hence, our required probability is 0.39.