Explore Westonci.ca, the premier Q&A site that helps you find precise answers to your questions, no matter the topic. Get quick and reliable solutions to your questions from a community of experienced professionals on our platform. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

The terminal side of angle θ intersects the unit circle in the first quadrant at x=2/5. What are the exact values of sinθ and cosθ?

Sagot :

Answer:

  • sin(θ) = (√21)/5
  • cos(θ) = 2/5

Step-by-step explanation:

You want the exact values of sine and cosine of the angle whose terminal point is at x=2/5 on the unit circle in the first quadrant.

Pythagorean identity

The coordinates of a point on the unit circle are (cos(θ), sin(θ)). You already know that the x-coordinate is 2/5, so ...

  cos(θ) = 2/5

The Pythagorean identity in trigonometric terms is ...

  sin²(θ) +cos²(θ) = 1

Then the sine of the angle is ...

  sin(θ) = √(1 -cos²(θ))

  sin(θ) = √(1 -(2/5)²) = √((25 -4)/25)

  sin(θ) = (√21)/5

The exact values of sine and cosine are ...

  • sin(θ) = (√21)/5
  • cos(θ) = 2/5
View image sqdancefan
Thanks for using our service. We aim to provide the most accurate answers for all your queries. Visit us again for more insights. We appreciate your time. Please come back anytime for the latest information and answers to your questions. Thank you for using Westonci.ca. Come back for more in-depth answers to all your queries.