Revision:Sin, Cos and Tan

TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Mathematics > Sin, Cos and Tan

(Diagram of triangle needed)

In any right angled triangle, for any angle:

The hypotenuse of a right angled triangle is the longest side, which is the one opposite the right angle. The adjacent side is the side which is between the angle in question and the right angle. The opposite side is opposite the angle in question.

Often remembered by: soh cah toa.

Example

Find the length of side x in the diagram below:

(diagram for question missing)

The angle is 60 degrees. We are given the hypotenuse and need to find the adjacent side. This formula which connects these three is:

therefore,

therefore,

therefore the length of side is 6.5cm.

The graphs of sin, cos and tan

The following graphs show the value of , and against ( represents an angle).

From the sin graph we can see that when = 0 degrees, 180 degrees and 360 degrees.

(diagram of graphs missing)

Comments

More is probably needed on the graphs for A and A* grade questions at Higher level GCSE.

This article is far too basic for the understanding of these topics at A Level (C1 module).

A look at contextual problems would be good, or a mentions of areas which are commonly connected with trig in exam questions would be useful.