What is the relationship between secant and cosecant in terms of acute angles?

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SUMMARY

The relationship between secant and cosecant for acute angles is established through the identity that if \(\tan(\alpha)\tan(\beta)=1\), then \(\sec(\alpha)=\csc(\beta)\). This conclusion arises from recognizing that angles \(\alpha\) and \(\beta\) are complementary, as demonstrated by rewriting \(\tan(\alpha)\) as \(\cot(\beta)\). The proof utilizes fundamental trigonometric identities, confirming that secant and cosecant are complementary functions by definition.

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karush
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If
$$\tan\left({\alpha}\right)\tan\left({\beta}\right)=1$$
$\alpha$ and $\beta$ are acute angles

Then
$$\sec\left({\alpha}\right)=\csc\left({\beta}\right)$$

Again there's options, I tried the product to sum formulas but it went off in a bad direction
 
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I would rewrite the given equation as:

$$\tan(\alpha)=\cot(\beta)$$

So, we can now easily see that $\alpha$ and $\beta$ are complementary. And so the result we are to prove follows, since secant and cosecant are complementary functions by definition. :)
 
$$\tan\alpha\tan\beta=1$$

$$\tan^2\alpha\tan^2\beta=1$$

$$(\sec^2\alpha-1)\tan^2\beta=1$$

$$\sec^2\alpha-1=\cot^2\beta$$

$$\sec^2\alpha=\cot^2\beta+1$$

$$\sec^2\alpha=\csc^2\beta$$

$$\sec\alpha=\csc\beta$$
 

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