I need help.
I got a problem that I didn't know how to slove.
Here are my questions.
1 . Find a six trigonometric function of an given angle. If any are not defined say 'no defined '
-7π/6
2. Find the exact value of the expression. Do not use a calculator.
6cosπ/4 - 5 sec π/6
請高手指教
謝謝！
Help! Math ! 函數!
2014-10-03 7:26 pm
回答 (1)
2014-10-04 3:25 am
✔ 最佳答案
1.
sin(-7π/6)
= sin(π/6)
= 1/2
cos(-7π/6)
= -cos(π/6)
= -√3/2
tan(-7π/6)
=-tan(π/6)
= -1/√3
= -√3/3
sec(-7π/6)
= 1 / [-(√3)/2]
= -2/√3
= -2√3/3
csc(-7π/6)
= 1 / (1/2)
= 2
cot(-7π/6)
= 1 / (-1/√3)
= -√3
====
2.
6cos(π/4) - 5sec(π/6)
= 6cos(π/4) - [5/cos(π/6)]
= 6[(√2)/2] - 5/[(√3)/2]
= (3√2) - (10/√3)
= (3√2) - [10√3/3]
= (9√2 - 10√3)/3
參考: 土扁
收錄日期: 2021-04-15 16:43:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20141003000051KK00021