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Verify the identity. cos^(2)xˢᵉᶜ²x+ᵗᵃⁿ²)x=ˢᵉᶜ²x

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Final answer:

Yes, the given trigonometric identity is true:
\( \cos^2(x) \sec^2(x) + \tan^2(x) = \sec^2(x) \).

Step-by-step explanation:

The given trigonometric identity involves various trigonometric functions. Let's break down the proof step by step.

Firstly, rewrite the expression using the definitions of secant and tangent:


\[ \cos^2(x) \sec^2(x) + \tan^2(x) = \cos^2(x) \left((1)/(\cos^2(x))\right) + (\sin^2(x))/(\cos^2(x)) \]

Simplify the expression by canceling out common terms:


\[ 1 + \tan^2(x) = \sec^2(x) \]

Now, recall the fundamental trigonometric identity
\(1 + \tan^2(x) = \sec^2(x)\), which confirms the given identity. Therefore, the original expression equals
\(\sec^2(x)\), proving the identity.

In summary, by manipulating the given expression using trigonometric definitions and known identities, we arrive at the conclusion that
\( \cos^2(x) \sec^2(x) + \tan^2(x) \) indeed equals \( \sec^2(x) \), verifying the identity.

User Abtin Forouzandeh
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