Q. Which of the following is equivalent to sec5π ?sec514πsec(−5π)sec56πsec54π
Properties of Secant Function: Understand the properties of the secant function. The secant function, sec(θ), is periodic with a period of 2π. This means that sec(θ)=sec(θ+2πk) for any integer k. Additionally, sec(−θ)=sec(θ) because secant is an even function.
Evaluate First Option: Evaluate the first option, sec(514π). Since the secant function has a period of 2π, we can subtract 2π from 514π until we are within the interval [0,2π). 514π−2π=514π−510π=54π. So, sec(514π) is equivalent to sec(54π).
Evaluate Second Option: Evaluate the second option, sec(−5π). Since the secant function is even, sec(−5π) is equivalent to sec(5π).
Evaluate Third Option: Evaluate the third option, sec(56π). Subtracting 2π from 56π gives us 56π−2π=56π−510π=−54π. Since secant is an even function, sec(−54π) is equivalent to sec(54π), which is not equivalent to sec(5π).
Evaluate Fourth Option: Evaluate the fourth option, sec(54π). This is not equivalent to sec(5π) because 54π is not equal to 5π plus any multiple of 2π.
Compare Results: Compare the results from Steps 2, 3, 4, and 5. The only equivalent expressions to sec(5π) are sec(−5π) from Step 3 and sec(514π) from Step 2, which simplifies to sec(54π). However, since sec(54π) is not equivalent to sec(5π), there must be a mistake in the previous steps.
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