How can this expression 8 cos (arcsin x/4) be rewritten without trigonometric function?
Thank you for your answer and explanation.
Rewriting an expression
2014-03-31 2:16 am
回答 (1)
2014-03-31 5:30 am
✔ 最佳答案
consider a right angled-triangle with angle θs.t. sinθ=x/4
i.e. opposite side=x , hypotenuse=4
∴adjacent side=√(4^2-x^2)=√(16-x^2) (Pyth. theorem)
8 cos(arcsin x/4)
=8cosθ
=8(√(16-x^2) / 4)
=2√(16-x^2)
收錄日期: 2021-04-13 20:20:11
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