1.)Lawrence walks 200m up a slope with the gradient of 1/5.What is his vertical rise??
2.)A ship sails 15 km to the east fromA to B,and then sails 10 km to the north to C.Find the bearinf of a from c.(correct your answer to 1 decimal place.)
有冇人可以幫我解答以下一些數學問題ar??>.
2008-08-28 9:30 am
回答 (2)
2008-08-28 4:43 pm
✔ 最佳答案
1) 佢所講的200m 應該是一個直角三角形的斜邊,而gradient of 1/5就係vertical rise / horizontal run,
所以你要先找出gradient of 1/5即係代表幾度.
Let tanA be the gradient 1/5,
tanA = 1/5
A = 11.3度 (Corr.to 3sig.fig)
Let xm be the length of his vertical rise,
sin11.3度 = x/200
x = 39.2 (Corr.to 3sig.fig)
2) angle ACB= <ACB (唔識打個ANGLE 符號)
AC^2 = 15^2 + 10^2
AC=√(325)
cos <ACB= 10/ (√325) (你要知道angel ABC 是90度!)
<ACB= 56.3度 (Corr.to 1d.p.)
The bearing is S 56.3度 W
2008-08-31 14:11:46 補充：
你諗得太多。
參考: myself( 但answer不一定對!)
2008-08-28 9:32 pm
你唔係話英文好confusing咩, e+咪一樣答得好好地
睇嚟你都係想線我多wor~
睇嚟你都係想線我多wor~
收錄日期: 2021-04-13 16:48:48
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