知幾多答幾多,thx!!點做??-.-'"
1.Calculate each of the following and give answer in scientifc notation.
a.8x10^4+7x10^4
e.(3x10^8)x(6x10^-3)
g.(2.55x10^-3)/(5x10^-7)
2.tan sin cos(三角形圖)點做
3.Find th values of the following without using a calculator
a.sin^2 45'/tan 45'
b.tan30' tan60'+sin45' cos45'
d.cos60'/(tan45'-sin30')^2
e.1/sin60'+cos30'/sin45'
4.Given that sin0=8/11,find the values of cos0andtan0.(in surd form)
急...F3.mathsT.T
2008-01-01 9:12 am
回答 (1)
2008-01-01 10:39 am
✔ 最佳答案
1. a. 15X10^4 = 1.5X10^5e. 18X10^5 = 1.8X10^6
g. 0.51X10^4 = 5.1X10^3
3. a. sin^2 45' / tan 45' = sin 45' cos 45' = 1/2 sin 90' = 1/2
b. tan 30' tan 60' + sin45' cos45' = 1+1/2 = 3/2
d. cos 60' / (tan45'-sin30')^2 = 1/2 / (1-1/2)^2 = 2
e. 1/sin60' + cos30'/sin45' = 2/(3)^1/2 + (3)^1/2 /2 X 2 = (2X(2)^1/2 + 3) / (6)^1/2
4. cos 0 = (57)^1/2 / 11 tan 0 = 8 / (57)^1/2
參考: 自己
收錄日期: 2021-04-13 14:50:41
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080101000051KK00204