LibGuides: DIY Maths: Introduction to sine, cosine and tangent

INTRODUCTION TO SINE, COSINE AND TANGENT

In this module, you can study how to calculate sine, cosine and tangent for the angles of a right triangle; how to use SohCahToa to remember the formulae for calculating sine, cosine and tangent.

Did you know?

"Adjacent" and "opposite" sides can change, depending on which angle you start from.

"Cos(x)" means "the cosine of x degrees"; it does NOT mean multiply the cosine by x.

Study and practice

Study introductory trigonometry
Mathsisfun.com has written a good introductory lesson on trigonometry, which includes definitions, graphics and manipulatives. You don't need to read the whole page - only up to "Unit Circles".
Quiz yourself on calculating sine, cosine and tangent
Use this six-question quiz from onlinemathlearning.com for a quick online check of your trig knowledge.

Search Google

Use these search terms to find your own resources:

trigonometry ratios
introduction to trigonometry
definition of sine
definition of cosine
definition of tangent
sohcahtoa