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Verify each identity. 11. cot²x-tan²x=cosec²x-sec²x

User K Vij
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Final answer:

The trigonometric identity cot²x - tan²x = cosec²x - sec²x can be verified by rewriting cot and tan in terms of sine and cosine, and simplifying both sides using these relations.

Step-by-step explanation:

The student has asked to verify the trigonometric identity cot²x - tan²x = cosec²x - sec²x. To do this, we'll rewrite each term using basic trigonometric identities and show that both sides of the equation are equal.

Starting with the left side of the identity:

  • cot²x can be written as (cos²x/sin²x)
  • tan²x can be expressed as (sin²x/cos²x)

Similarly, for the right side of the identity:

  • cosec²x, which is 1/sin²x
  • sec²x, which is 1/cos²x

Now, we rewrite the equation as:

(cos²x/sin²x) - (sin²x/cos²x) = (1/sin²x) - (1/cos²x)

With common denominators, we get:

((cos´x - sin´x) / (sin²x cos²x)) = ((cos²x - sin²x) / (sin²x cos²x))

Note that cos´x - sin´x can be factored into (cos²x + sin²x)(cos²x - sin²x), and since cos²x + sin²x = 1, we have:

(1)(cos²x - sin²x) / (sin²x cos²x)

Thus, proving the identity cot²x - tan²x = cosec²x - sec²x.

User Ebonnal
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