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What are all the exact solutions of 2sec^2x-tan^4x=-1 ?

User Sital
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Final answer:

To find the exact solutions of the given equation 2sec^2x-tan^4x=-1, we can simplify the equation using trigonometric identities and solve for tanx. The solutions are x = pi/3 + n*pi for tanx = sqrt(3), and x = -pi/4 + n*pi for tanx = -1.

Step-by-step explanation:

The given equation is 2sec^2x-tan^4x=-1. To solve this equation, we need to simplify the trigonometric terms using known identities. The identity sec^2x = 1 + tan^2x can be used here. Substituting this identity into the equation gives us 2(1 + tan^2x) - tan^4x = -1. Simplifying further, we have 2 + 2tan^2x - tan^4x = -1. Rearranging the terms, we get tan^4x - 2tan^2x - 3 = 0.

Now, let's substitute tan^2x with u, giving us the equation u^2 - 2u - 3 = 0. This is a quadratic equation that can be factored as (u - 3)(u + 1) = 0. Solving for u, we have u = 3 or u = -1. Substituting back tan^2x for u, we get tan^2x = 3 or tan^2x = -1. Taking the square root of both sides, we have tanx = sqrt(3) or tanx = -1.

Finally, to find the exact solutions of x, we need to consider the periodic nature of trigonometric functions. Since tanx repeats every pi radians, the solutions are x = pi/3 + n*pi, where n is an integer, for tanx = sqrt(3), and x = -pi/4 + n*pi, for tanx = -1.

User Kayani
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Answer:

A

Step-by-step explanation:

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User BConic
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