中四數.證明 tan^(180-x)/1+tan^2x = sin^2x

2008-06-08 6:34 pm

證明 tan^(180-x)/1+tan^2x = sin^2x

回答 (5)

2008-06-08 7:15 pm

✔ 最佳答案

[tan2(180-x)]/(1+tan2x) = sin2x
左方=[tan2(180-x)]/(1+tan2x)
=tan2x /sec2x
=(sin2x/cos2x) (cos2x)
=sin2x
=右方

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2008-06-08 7:53 pm

LHS=tan²(180-x)/(1+tan²x)
=tan²x/(1+tan²x)
=tan²x/sec²x
=sin²x
=RHS

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2008-06-08 7:47 pm

係,係[tan^2(180-x)]/(1+tan^2x) = sin^2x

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2008-06-08 6:54 pm

問題不清晰WOR
都唔知你打咩
加D括號啦

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2008-06-08 6:42 pm

tan^(180-x)是不是打少左d野?

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