Let (-4,-5) be a point on the terminal side of an angle in standard position. Evaluate the six trigonometric functions of 0

1 answer

To find the six trigonometric functions for the angle whose terminal side passes through the point \((-4, -5)\), we first calculate the radius \(r\), which is the distance from the origin to the point \((-4, -5)\). This is done using the distance formula:

\[ r = \sqrt{x^2 + y^2} \]

Substituting \(x = -4\) and \(y = -5\):

\[ r = \sqrt{(-4)^2 + (-5)^2} = \sqrt{16 + 25} = \sqrt{41} \]

Now we can find the six trigonometric functions:

  1. Sine (\(\sin\)): \[ \sin(\theta) = \frac{y}{r} = \frac{-5}{\sqrt{41}} \]

  2. Cosine (\(\cos\)): \[ \cos(\theta) = \frac{x}{r} = \frac{-4}{\sqrt{41}} \]

  3. Tangent (\(\tan\)): \[ \tan(\theta) = \frac{y}{x} = \frac{-5}{-4} = \frac{5}{4} \]

  4. Cosecant (\(\csc\)): \[ \csc(\theta) = \frac{r}{y} = \frac{\sqrt{41}}{-5} \quad (\text{undefined when } y = 0) \]

  5. Secant (\(\sec\)): \[ \sec(\theta) = \frac{r}{x} = \frac{\sqrt{41}}{-4} \]

  6. Cotangent (\(\cot\)): \[ \cot(\theta) = \frac{x}{y} = \frac{-4}{-5} = \frac{4}{5} \]

Summarizing the results:

  • \(\sin(\theta) = \frac{-5}{\sqrt{41}}\)
  • \(\cos(\theta) = \frac{-4}{\sqrt{41}}\)
  • \(\tan(\theta) = \frac{5}{4}\)
  • \(\csc(\theta) = \frac{\sqrt{41}}{-5}\)
  • \(\sec(\theta) = \frac{\sqrt{41}}{-4}\)
  • \(\cot(\theta) = \frac{4}{5}\)

These are the six trigonometric functions for the angle whose terminal side passes through the point \((-4, -5)\).