20xx年電大工程數(shù)學(xué)試卷及答案小抄參考-資料下載頁(yè)
2025-10-02 01:40本頁(yè)面
【導(dǎo)讀】A=A1∪A2∪A3表示()。A.全部擊中.B.至少有一發(fā)擊中.2．對(duì)于任意兩個(gè)隨機(jī)變量X和Y，若E=EE，則有()。3．下列各函數(shù)中可以作為某個(gè)隨機(jī)變量的概率密度函數(shù)的是（）。，才有P1=P2D.對(duì)于任意的?將其代碼填在題后的括號(hào)內(nèi)。錯(cuò)選或未選均無分。正常工作的概率為。)(的傅氏變換(這里0??12．發(fā)報(bào)臺(tái)分別以概率和發(fā)出信號(hào)“1”和“0”?？赡艿?，求有球盒子數(shù)X的數(shù)學(xué)期望。15．設(shè)一口袋中依此標(biāo)有1，2，2，2，3，3數(shù)字的六個(gè)球。,an)T，a1≠0,其長(zhǎng)度為║a║，又A=aaT,證明A2=║a║2A；證明a是A的一個(gè)特征向量，而0是A的n-1重特征值；A能相似于對(duì)角陣Λ嗎？每噸需保養(yǎng)費(fèi)1萬元。問需要組織多少貨源，才能使國(guó)家收益最大。
【正文】 ersonic descent could happen as early as Sunda. The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our daytoday weather lives. It will climb higher than the tip of Mount Everest ( miles/ kilometers), drifting even higher than the cruising altitude of mercial airliners ( miles/ kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence. The balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would 專業(yè)好文檔 《工程數(shù)學(xué)》試題 第 13 頁(yè) 共 6 頁(yè) assume, he will slowly step out onto something resembling an Olympic diving platform. Below, the Earth bees the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, he39。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely. If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。s not needed. Instead, he plans to deploy his 270squarefoot (25squaremeter) main chute at an altitude of around 5,000 feet (1,524 meters). In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds. Even if everything goes as planned, it won39。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there
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