Questions: Let cos θ=2, with 3π<θ<2π. Solve for the remaining trig values:
(d) csc θ=
(e) cot θ=
Transcript text: Let $\cos \theta=2$, with $3 \pi<\theta<2 \pi$. Solve for the remaining trig values:
(d) $\csc \theta=$
(e) $\cot \theta=$
Solution
Solution Steps
To solve for the remaining trigonometric values given that \(\cos \theta = 2\) and \(3\pi < \theta < 2\pi\), we need to recognize that \(\cos \theta = 2\) is not possible since the range of the cosine function is \([-1, 1]\). Therefore, there must be an error in the given problem. However, if we assume a hypothetical scenario where \(\cos \theta\) could be 2, we would use the definitions of the trigonometric functions to find \(\csc \theta\) and \(\cot \theta\).
Solution Approach
Recognize that \(\cos \theta = 2\) is not possible within the range of the cosine function.
If we hypothetically proceed, we would use the definitions of \(\csc \theta\) and \(\cot \theta\):
\(\csc \theta = \frac{1}{\sin \theta}\)
\(\cot \theta = \frac{\cos \theta}{\sin \theta}\)
Since \(\cos \theta = 2\), we would need to find \(\sin \theta\) using the Pythagorean identity, but this would lead to an imaginary number.
Step 1: Recognize the Given Value and Its Implications
Given \(\cos \theta = 2\), we note that this value is outside the range of the cosine function, which is \([-1, 1]\). However, for the sake of the problem, we proceed with the given value.
Step 2: Calculate \(\sin \theta\) Using the Pythagorean Identity
The cosecant function is defined as:
\[
\csc \theta = \frac{1}{\sin \theta}
\]
Substituting the value of \(\sin \theta\):
\[
\csc \theta = \frac{1}{1.7321i} \approx -0.5774i
\]
Step 4: Calculate \(\cot \theta\)
The cotangent function is defined as:
\[
\cot \theta = \frac{\cos \theta}{\sin \theta}
\]
Substituting the values of \(\cos \theta\) and \(\sin \theta\):
\[
\cot \theta = \frac{2}{1.7321i} \approx -1.1547i
\]