Stitz-Zeager_College_Algebra_e-book

3 with in quadrant ii 5 12 with in quadrant iii b tan

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: = −π 3. θ = 45◦ 4. θ = π 6 5. θ = 60◦ Solution. 1. To find cos (270◦ ) and sin (270◦ ), we plot the angle θ = 270◦ in standard position and find the point on the terminal side of θ which lies on the Unit Circle. Since 270◦ represents 3 of a 4 counter-clockwise revolution, the terminal side of θ lies along the negative y -axis. Hence, the π π point we seek is (0, −1) so that cos 32 = 0 and sin 32 = −1. 2. The angle θ = −π represents one half of a clockwise revolution so its terminal side lies on the negative x-axis. The point on the Unit Circle which lies on the negative x-axis is (−1, 0) which means cos(−π ) = −1 and sin(−π ) = 0. 1 The etymology of the name ‘sine’ is quite colorful, and the interested reader is invited to research it; the ‘co’ in ‘cosine’ is explained in Section 10.4. 10.2 The Unit Circle: Cosine and Sine 613 y y 1 1 θ = 270◦ P (−1, 0) x 1 x 1 θ = −π P (0, −1) Finding cos (270◦ ) and sin (270◦ ) Finding cos (−π ) and sin (−π ) 3...
View Full Document

This note was uploaded on 05/03/2013 for the course MATH Algebra taught by Professor Wong during the Fall '13 term at Chicago Academy High School.

Ask a homework question - tutors are online