LibGuides: Math Help: 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".
Read about the sine ratio
How to determine and use sines.
Read about the cosine ratio
How to find and use cosines.
Read about the tangent ratio
Read about how to find and use tangents.
Download an intro to trig worksheet
This downloadable worksheet from mathworksheetsgo.com contains sample problems, problem sets and all answers. It covers the identification of adjacent sides, opposite sides and hypotenuse as well as the calculation of sine, cosine and tangent.
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.