Answer:
2.4 hours
Step-by-step explanation:
Let total work = X
Rate of work done = X ÷ time
Rate of A = X/4
Rate of B = X/6
If they work together, rate is the sum of their individual rates, i.e.
X/4 + X/6
= (3X + 2X)/12 (taking LCM)
=5X/12
Rate = X/time
5X/12 = X/time
time = X÷(5X/12)
time = X × 12/(5X)
time = 2.4 hours
Shortcut:
Product of individual times/sum of individual times
= (4×6)/(4+6)
=24/10
=2.4 hours
Answer:
C≈18.85
Step-by-step explanation:
have a nice day!
Answer:
80 degrees
Step-by-step explanation:
Answer:
The value of the expression given is:
Step-by-step explanation:
First, you must divide the expression in three, and to the final, you can multiply it:
- [(3^8)*(2^(-5))*(9^0)]^(-2)
- [(2^(-2))/(3^3)]^4
- 3^28
Now, we can solve each part one by one:
<em>First part.
</em>
- 3^8 = 6561
- 2^(-5) = 0.03125
- 9^0 = 1 (Whatever number elevated to 0, its value is 1)
- (6561 * 0,03125 * 1) = 205.03125
And we elevate this to -2:
- 205.03125^-2 = 2<u>.378810688*10^(-5)</u> or <u>0.00002378810688
</u>
<em>Second part.
</em>
- 2^(-2) = 0.25
- 3^3 = 27
- 0.25 / 27 = 9.259259259 * 10^(-3) or 0.00925925925925
And we elevate this to 4:
- 0.00925925925925^4 = <u>7.350298528 * 10^(-9)</u> or <u>0.000000007350298528
</u>
<em>Third Part.
</em>
- 3^28 = <u>2.287679245 * 10^13</u> or <u>22876792450000</u>
At last, we multiply all the results obtained:
- 0.00002378810688 * 0.000000007350298528 * 22876792450000 = <u>3.999999999999999999</u> approximately <u>4</u>
<u><em>We approximate the value because the difference to 4 is minimal, which could be obtained if we use all the decimals in each result</em></u>.
Answer:
A) ![\left[\begin{array}{cc}0&-1\\1&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D0%26-1%5C%5C1%260%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
The rotation matrix for a clockwise rotation through angle θ is given by ...
![M=\left[\begin{array}{cc}\cos{(\theta)}&-\sin{(\theta)}\\\sin{(\theta)}&\cos{(\theta)}\end{array}\right]](https://tex.z-dn.net/?f=M%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D%5Ccos%7B%28%5Ctheta%29%7D%26-%5Csin%7B%28%5Ctheta%29%7D%5C%5C%5Csin%7B%28%5Ctheta%29%7D%26%5Ccos%7B%28%5Ctheta%29%7D%5Cend%7Barray%7D%5Cright%5D)
When θ = 90°, the matrix becomes the one in choice A).
