Name: ___________________


kwizNET Subscribers, please login to turn off the Ads!
Email us to get an instant 20% discount on highly effective K-12 Math & English kwizNET Programs!

High School Mathematics - 2
10.8 Signs of Trigonometric Functions for Negative Angles

θsin θ cos θtan θ cosec θ sec θ cot θ
Signs of trigonometric functions for negative angles
Let P(x,y) be a point on the unit circle with centre at origin such that angle AOP = θ. If angle AOQ = -θ, then the co-ordinates of the point Q will be (x,-y). Hence
cos(-θ) = x = cosθ
sin(-θ) = -y = -sinθ
sinθ ++--
cosθ +--+
tanθ +-+-
cosecθ ++--
secθ +--+
cotθ +-+-
In the first quadrant, as θ increases from 0 to π/2, sinθ increases from 0 to 1.
In the second quadrant, as θ increases from to π/2 to π,to π sinθ decreases from 1 to 0.
In the third quadrant, as θ increases from π to 3π/2, sinθ decreases from 0 to -1.
In the fourth quadrant, sinθ increases from -1 to 0, as θ increases from 3π/2 to 2π.

Directions: Solve the following.
Q 1: State the quadrants in which cos x = .7331 may lie.

Question 2: This question is available to subscribers only!

Subscription to kwizNET Learning System costs less than $1 per month & offers the following benefits:

  • Unrestricted access to grade appropriate lessons, quizzes, & printable worksheets
  • Instant scoring of online quizzes
  • Progress tracking and award certificates to keep your student motivated
  • Unlimited practice with auto-generated 'WIZ MATH' quizzes
  • Child-friendly website with no advertisements

© 2003-2007 kwizNET Learning System LLC. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. For permission, contact
For unlimited printable worksheets & more, go to