Questions: The point given below is on the terminal side of an angle θ. Find the exact value of each of the six trigonometric functions of θ.
(-8,6)
Transcript text: The point given below is on the terminal side of an angle $\theta$. Find the exact value of each of the six trigonometric functions of $\theta$.
\[
(-8,6)
\]
Solution
Solution Steps
Step 1: Calculate the Hypotenuse
To find the hypotenuse \( r \) of the right triangle formed by the point \((-8, 6)\), we use the Pythagorean theorem:
\[
r = \sqrt{x^2 + y^2} = \sqrt{(-8)^2 + 6^2} = \sqrt{64 + 36} = \sqrt{100} = 10
\]
Step 2: Calculate Sine
The sine of the angle \( \theta \) is given by:
\[
\sin(\theta) = \frac{y}{r} = \frac{6}{10} = \frac{3}{5}
\]
Thus, the exact value is:
\[
\sin(\theta) = \frac{3}{5}
\]
Step 3: Calculate Cosine
The cosine of the angle \( \theta \) is given by:
\[
\cos(\theta) = \frac{x}{r} = \frac{-8}{10} = -\frac{4}{5}
\]
Thus, the exact value is:
\[
\cos(\theta) = -\frac{4}{5}
\]
Step 4: Calculate Tangent
The tangent of the angle \( \theta \) is given by:
\[
\tan(\theta) = \frac{y}{x} = \frac{6}{-8} = -\frac{3}{4}
\]
Thus, the exact value is:
\[
\tan(\theta) = -\frac{3}{4}
\]
Step 5: Calculate Cosecant
The cosecant is the reciprocal of sine:
\[
\csc(\theta) = \frac{1}{\sin(\theta)} = \frac{1}{\frac{3}{5}} = \frac{5}{3}
\]
Thus, the exact value is:
\[
\csc(\theta) = \frac{5}{3}
\]
Step 6: Calculate Secant
The secant is the reciprocal of cosine:
\[
\sec(\theta) = \frac{1}{\cos(\theta)} = \frac{1}{-\frac{4}{5}} = -\frac{5}{4}
\]
Thus, the exact value is:
\[
\sec(\theta) = -\frac{5}{4}
\]
Step 7: Calculate Cotangent
The cotangent is the reciprocal of tangent:
\[
\cot(\theta) = \frac{1}{\tan(\theta)} = \frac{1}{-\frac{3}{4}} = -\frac{4}{3}
\]
Thus, the exact value is:
\[
\cot(\theta) = -\frac{4}{3}
\]