Math Problem Statement

Given sine 3/5 the angle in lies in quadrant 2. Find the exact value of 6 trigonometric functions.

Solution

We are given that sin(θ)=35\sin(\theta) = \frac{3}{5} and that the angle θ\theta lies in quadrant II. To find the exact values of all six trigonometric functions, let's use the given information and trigonometric identities. Here are the steps:

Step 1: Find cos(θ)\cos(\theta) and tan(θ)\tan(\theta)

We know that in quadrant II, sine is positive, but cosine is negative. We'll use the Pythagorean identity:

sin2(θ)+cos2(θ)=1\sin^2(\theta) + \cos^2(\theta) = 1

Substitute sin(θ)=35\sin(\theta) = \frac{3}{5}:

(35)2+cos2(θ)=1\left(\frac{3}{5}\right)^2 + \cos^2(\theta) = 1

925+cos2(θ)=1\frac{9}{25} + \cos^2(\theta) = 1

cos2(θ)=1925=2525925=1625\cos^2(\theta) = 1 - \frac{9}{25} = \frac{25}{25} - \frac{9}{25} = \frac{16}{25}

cos(θ)=±45\cos(\theta) = \pm \frac{4}{5}

Since θ\theta lies in quadrant II, cos(θ)\cos(\theta) must be negative:

cos(θ)=45\cos(\theta) = -\frac{4}{5}

Step 2: Find tan(θ)\tan(\theta)

Now, we can find tan(θ)\tan(\theta) using the identity:

tan(θ)=sin(θ)cos(θ)\tan(\theta) = \frac{\sin(\theta)}{\cos(\theta)}

Substitute the known values:

tan(θ)=3545=34\tan(\theta) = \frac{\frac{3}{5}}{-\frac{4}{5}} = -\frac{3}{4}

Step 3: Find csc(θ)\csc(\theta), sec(θ)\sec(\theta), and cot(θ)\cot(\theta)

Now, we use the reciprocal identities to find the other functions:

  • csc(θ)=1sin(θ)=135=53\csc(\theta) = \frac{1}{\sin(\theta)} = \frac{1}{\frac{3}{5}} = \frac{5}{3}
  • sec(θ)=1cos(θ)=145=54\sec(\theta) = \frac{1}{\cos(\theta)} = \frac{1}{-\frac{4}{5}} = -\frac{5}{4}
  • cot(θ)=1tan(θ)=134=43\cot(\theta) = \frac{1}{\tan(\theta)} = \frac{1}{-\frac{3}{4}} = -\frac{4}{3}

Final Answer:

The exact values of the six trigonometric functions are:

  1. sin(θ)=35\sin(\theta) = \frac{3}{5}
  2. cos(θ)=45\cos(\theta) = -\frac{4}{5}
  3. tan(θ)=34\tan(\theta) = -\frac{3}{4}
  4. csc(θ)=53\csc(\theta) = \frac{5}{3}
  5. sec(θ)=54\sec(\theta) = -\frac{5}{4}
  6. cot(θ)=43\cot(\theta) = -\frac{4}{3}

Would you like a more detailed explanation of any of these steps, or do you have any follow-up questions? Here are some related questions:

  1. How do I use the Pythagorean identity to find trigonometric values?
  2. How do the signs of trigonometric functions change in different quadrants?
  3. How can I derive trigonometric identities from basic relationships?
  4. What other methods can be used to find trigonometric functions if I know one?
  5. How can I visualize the relationship between sine, cosine, and tangent on the unit circle?

Tip: Remember that in quadrant II, sine is positive, cosine is negative, and tangent is negative as well.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Sine Function
Cosine Function
Tangent Function
Pythagorean Identity
Reciprocal Identities
Trigonometric Functions in Different Quadrants

Formulas

sin^2(θ) + cos^2(θ) = 1
tan(θ) = sin(θ) / cos(θ)
csc(θ) = 1 / sin(θ)
sec(θ) = 1 / cos(θ)
cot(θ) = 1 / tan(θ)

Theorems

Pythagorean Identity
Reciprocal Trigonometric Functions

Suitable Grade Level

Grades 10-12