Questions: Suppose cos(A) = 0.325
Use the trig identity sin^2(A) + cos^2(A) = 1 and the trig identity tan(A) = sin(A) / cos(A) to find tan(A) in quadrant IV. Round to ten-thousandth.
Transcript text: Suppose $\cos (A)=0.325$
Use the trig identity $\sin ^{2}(A)+\cos ^{2}(A)=1$ and the trig identity $\tan (A)=\frac{\sin (A)}{\cos (A)}$ to find $\tan (A)$ in quadrant IV. Round to ten-thousandth.
Solution
Solution Steps
To solve this problem, we need to find the value of \(\tan(A)\) given that \(\cos(A) = 0.325\) and \(A\) is in the fourth quadrant. We will use the trigonometric identity \(\sin^2(A) + \cos^2(A) = 1\) to find \(\sin(A)\). Since \(A\) is in the fourth quadrant, \(\sin(A)\) will be negative. Once we have \(\sin(A)\), we can calculate \(\tan(A)\) using the formula \(\tan(A) = \frac{\sin(A)}{\cos(A)}\).
Step 1: Given Information
We are given that \( \cos(A) = 0.325 \) and we need to find \( \tan(A) \) in the fourth quadrant.
Step 2: Calculate \( \sin(A) \)
Using the trigonometric identity \( \sin^2(A) + \cos^2(A) = 1 \), we can find \( \sin(A) \):
\[
\sin^2(A) = 1 - \cos^2(A) = 1 - (0.325)^2 = 1 - 0.105625 = 0.894375
\]
Taking the square root, we find:
\[
\sin(A) = -\sqrt{0.894375} \approx -0.9457
\]
(Note: We take the negative root because \( A \) is in the fourth quadrant.)
Step 3: Calculate \( \tan(A) \)
Now, we can calculate \( \tan(A) \) using the formula:
\[
\tan(A) = \frac{\sin(A)}{\cos(A)} = \frac{-0.9457}{0.325} \approx -2.9099
\]
Final Answer
Thus, the value of \( \tan(A) \) rounded to four decimal places is:
\[
\boxed{\tan(A) = -2.9099}
\]