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What does it mean that the probability of a thing is negative? Er It means the brain is in a mess
If the calculation is wrong, do it again. Correctly use permutation and combination to calculate the possible situation of the event
Mathematical probability problem: if the success rate of a thing is 1%, what is the probability of at least one success after 100 repeated attempts?
If the success rate of an event is 1%, what is the probability of at least one success after 100 repeated attempts? There are four alternative answers: 10%, 23%, 38% and 63%
Please explain! Thank you!
On the other hand, the probability of failure is 99% to the 100th power, which is equal to 0.3660323412732, which is about 0.37, and the probability of success at least once is 63%
80% of the number a is equal to 75% of the number B. what is the number B?
Let a be x and B be y
0.8x=0.75y
x：y=0.75：0.8
=15：16
B is 15 / 16 of A
Li Ming plans to finish a Book of 200 pages in a certain period of time. After five days, he changes his plan and reads five more pages every day
Li Ming plans to finish a Book of 200 pages in a certain period of time. After reading it for five days, he changes his plan and reads five more pages every day. If Li Ming originally plans to read x pages every day, he uses the formula containing x to express the following quantity. Li Ming originally plans to read this book for () days. When he changes his plan, he has read () pages and has () pages left
Li Ming plans to finish a Book of 200 pages in a certain period of time. After five days, he changes his plan and reads five more pages a day. If Li Ming originally plans to read x pages a day, he uses the formula containing x to express the following quantity. Li Ming originally plans to read this book in (200 △ x) days. When he changes his plan, he has read (5x) pages and has (200-5x) pages left
Solution equation: (x + 1) ^ 4 + (x + 3) ^ 4 = 82
Hope to write the process, more detailed, thank you!
Let y = x + 2
Then (x + 1) ^ 4 + (x + 3) ^ 4
=(y-1)^4 + (y+1)^4
=[(y-1)²+(y+1)²]² - 2(y-1)²(y+1)²
=(2y²+2)² -2(y²-1)²
=4y^4 + 8y² + 4 - 2y^4 +4y²-2
=2y^4 + 12y²+2 = 82
therefore
y^4 + 6y² = 40
(y²+3)² = 49
y²+3 = 7
y² = 4
y=±2
X = 0, or x = - 4
Divide the two meter long wood into seven sections. How many parts of each section is one meter long?
The two meter long wood is divided into seven sections, one seventh of the length of each section, which is two seventh of one meter
Let f (x) = x * (x-1) * (X-2)... (x-99) (X-100), then f '(0)=
Because f (x) = x * (x-1) * (X-2)... (x-99) (X-100), f (0) = 0, so f '(0) = LIM (x → 0) [f (x) - f (0)] / (x-0) = LIM (x → 0) f (x) / x = LIM (x → 0) [x * (x-1) * (X-2)... (x-99) (X-100)] / x = LIM (x → 0) (x-1) * (X-2)... (x-99) (X-100) = (0-1) * (0-2)... (0-9
Solving the equation (24 19:31:18)
(1) Xsquare - 5x = 0 & # - 160; - # - 160; - # - 160; - # - 160; - # - 160; - # - 160; - # - 160; - # - 160; - # - 160; (2) (3x-2) square = (1-5x) square
1 x²-5x=0 x*x=5*x x=5
2 (3x-2)²=（1-5x)² 3x-2=1-5x 3x-2+5x=1 8x=3 x=3/8=0.375
What's two out of three
RT, urgent
Tan2 π / 3 = Tan (π - π / 3) = - Tan π / 3 = - radical 3
Can the minus sign before acceleration indicate the size, such as - 20 or 5?
Acceleration is a vector and cannot be directly compared with size. The sign in front of it indicates the direction of acceleration relative to the positive direction you take. The sign in the same direction reverses. If you have to compare the acceleration, let the acceleration of object a be - 20 and that of object B be 5. It can only be said that the acceleration of object a is greater than that of object B
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