What Are the Critical Numbers for the Function f(θ) = 2sec(θ) + tan(θ)?

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SUMMARY

The critical numbers for the function f(θ) = 2sec(θ) + tan(θ) are determined by analyzing its derivative, f'(x) = 2sec(x)tan(x) + sec²(x). The critical points occur where the derivative equals zero or is undefined. Since sec(x) is never zero, the critical numbers arise from the equation 2tan(x) + sec(x) = 0. This leads to identifying values of x where the tangent function and secant function interact, specifically where sec(x) is undefined.

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  • Study the behavior of secant and tangent functions to identify their undefined points.
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Homework Statement



f(theta)=2sec(theta)+tan(theta)

The Attempt at a Solution


I found the derivative and set it equal to zero and to reduce writing I substituted x for theta
f'(x)=2sec(x)tan(x)+sec^2(x)
sec(x)[2tan(x)+sec(x)]=0

My question is what are the critical numbers? do the critical numbers exist where sec(x) is underfined because sec(x) will never equal 0.
 
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The expression can be further simplified:
<br /> \sec^{2}x(2\sin x+1)=0<br />
as sec(x) is never zero, we can divide through by it and not loose any solutions. What are you left with?
 
sec(x)[2tan(x)+sec(x)] = 0

You are trying to find an x to make the left side equal to 0.

Like you said, there is no x for which sec(x) = 0, so you can discard that possibility.

How else can the left side of that equation be 0?
 

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