UC知道关于立体几何的三角函数~英文的题目~~~读懂困难不大~~
来源：百度知道 编辑：UC知道 时间：2024/05/18 00:36:15
·Q1·
David walks along a straight road. At one point he notices a tower on a bearing of 053°with an angel of elevation of 21°. After walking 230m ,the tower is on a bearing of 342°,with an angle of elevation of 26°.Find the height of the tower correct to the nearest metre
·Q2·
A cylinder with radius 4cm and perpendicular height 15cm is tilted so that it will just fit inside a 12cm high box. At what angle must it be tilted? (此题有图，但不便画出~依照题目画出图应该不难~~望见谅)
·Q3·
A hot air balloon flying at 950m/h at aconstant altitude of 3000m is observed to have an angel of elevation of 78°.After 20 minutes, the angle of elevation is 73°.Calculate the angle through which the observer has turned during those 20 minutes~~(此题有图，但不便画出~依照题目画出图应该不难~~望见谅)
拜托各位高手~~先感谢一下~~~^_^
我这里有书后面的答案~~但我不知道是不是都是正确的~~Q1:84m Q2:16°50′ Q3：11°10′
David walks along a straight road. At one point he notices a tower on a bearing of 053°with an angel of elevation of 21°. After walking 230m ,the tower is on a bearing of 342°,with an angle of elevation of 26°.Find the height of the tower correct to the nearest metre
·Q2·
A cylinder with radius 4cm and perpendicular height 15cm is tilted so that it will just fit inside a 12cm high box. At what angle must it be tilted? (此题有图，但不便画出~依照题目画出图应该不难~~望见谅)
·Q3·
A hot air balloon flying at 950m/h at aconstant altitude of 3000m is observed to have an angel of elevation of 78°.After 20 minutes, the angle of elevation is 73°.Calculate the angle through which the observer has turned during those 20 minutes~~(此题有图，但不便画出~依照题目画出图应该不难~~望见谅)
拜托各位高手~~先感谢一下~~~^_^
我这里有书后面的答案~~但我不知道是不是都是正确的~~Q1:84m Q2:16°50′ Q3：11°10′
1 设塔高为X，y为走了230米后离塔底的距离，则有
cot21=(230+y)/x
cot26=y/x
cot21 - cot26 = 230/x
x=230/(cot21 - cot26)= 418.2
2 12cm高的盒子，边长是根号（15^2-12^2）=9cm
倾斜角度是53度
3 20min上升了950/3米,设气球到天使水平直线距离x，第二次上升到
950/3 * 2的点到天使下方水平直线距离为Y
有：tan78=(x+950/3 * 2)/y
tan73=(x+950/3)/y
tant=x/y
解x=405.73 y=220.86
tant=1.84
所以t=61.5度
你把图贴出来