As usual, draw a diagram. You can easily see that if you are x away from the wall,
<span>the angle of elevation of the bottom of the screen (A) is </span>
<span>cotA = x/3 </span>
<span>A = arccot(x/3) </span>
<span>angle B to the top is </span>
<span>cotB = x/10 </span>
<span>B = arccot(x/10) </span>
<span>So, since θ = B-A </span>
<span>dθ/dt = dB/dt - dA/dt </span>
<span>= -3/(x^2+9) + 10/(x^2+100) </span>
<span>= 7(x^2-30)/((x^2+9)(x^2+100)) </span>
<span>so, at x=30 </span>
<span>dθ/dt = 203/30300</span>
Answer:
84? Not sure but pretty sure
Step-by-step explanation:
In a straight line, the word can only be spelled on the diagonals, and there are only two diagonals in each direction that have 2 O's.
If 90° and reflex turns are allowed, then the number substantially increases.
Corner R: can only go to the adjacent diagonal O, and from there to one other O, then to any of the 3 M's, for a total of 3 paths.
2nd R from the left: can go to either of two O's, one of which is the same corner O as above. So it has the same 3 paths. The center O can go to any of 4 Os that are adjacent to an M, for a total of 10 more paths. That's 13 paths from the 2nd R.
Middle R can go the three O's on the adjacent row, so can access the three paths available from each corner O along with the 10 paths available from the center O, for a total of 16 paths.
Then paths accessible from the top row of R's are 3 +10 +16 +10 +3 = 42 paths. There are two such rows of R's so a total of 84 paths.
Answer:
i doing the same problem like this, i was too lazy to do it but since there is no answer on the internet, here you are :
High category : 58%
Medium category : 61.0%
Step-by-step explanation:
Explain : like i said, i have a same question :D
Percent of red lights last between 2.5 and 3.5 minutes is 95.44% .
<u>Step-by-step explanation:</u>
Step 1: Sketch the curve.
The probability that 2.5<X<3.5 is equal to the blue area under the curve.
Step 2:
Since μ=3 and σ=0.25 we have:
P ( 2.5 < X < 3.5 ) =P ( 2.5−3 < X−μ < 3.5−3 )
⇒ P ( (2.5−3)/0.25 < (X−μ)/σ < (3.5−3)/0.25)
Since, Z = (x−μ)/σ , (2.5−3)/0.25 = −2 and (3.5−3)/0.25 = 2 we have:
P ( 2.5<X<3.5 )=P ( −2<Z<2 )
Step 3: Use the standard normal table to conclude that:
P ( −2<Z<2 )=0.9544
Percent of red lights last between 2.5 and 3.5 minutes is 
% .
Answer:
<h3>Option 4: y = 3 – 2a</h3>
Step-by-step explanation:
Given the simultaneous equation;
ax + by = ab ......... 1
2ax + 3by = 3b .....2
Required
Express y in terms of a
Using elimination method to eliminate x variable.
eqn 1 * 2 and eqn 2 *1 will give;
2ax + 2by = 2ab
2ax + 3by = 3b
Subtract
2by - 3by = 2ab - 3b
-by = 2ab - 3b
-by = b(2a-3)
-y = 2a-3
multiply through by -1
y = -2a + 3
y = 3-2a
Hence the value of y in terms of a is y = 3-2a
