Trigonometry

IGCSE 0580

Topic: Trigonometry

Core: C6.2

Extended: E6.2, E6.3, E6.4, E6.5, E6.6

Know and use the sine, cosine and tangent ratios for acute angles in calculations involving sides and angles of a right-angled triangle.
Solve problems in two dimensions using Pythagoras’ theorem and trigonometry.
Know that the perpendicular distance from a point to a line is the shortest distance to the line.
Carry out calculations involving angles of elevation and depression.
Know the exact values of:
sin x and cos x for x = 0°, 30°, 45°, 60° and 90°.
tan x for x = 0°, 30°, 45° and 60°.
Recognise, sketch and interpret the following graphs for 0° ⩽ x ⩽ 360°:
• y = sin x
• y = cos x
• y = tan x
Solve trigonometric equations involving sin x, cos x or tan x, for 0° ⩽ x ⩽ 360°.
Use the sine and cosine rules in calculations involving lengths and angles for any triangle.
Use the formula area of triangle = ½ ab sin C.
Carry out calculations and solve problems in three dimensions using Pythagoras’ theorem and trigonometry, including calculating the angle between a line and a plane.

Sine and what it actually means?

In this video I'll explain a little about what sine is. This is not necessarily something that will be asked in an exam, but it will help you to have an idea of what the sine of an angle "tells us"

Cosine and what it actually means?

In this video I'll explain a little about what cosine is. This is not necessarily something that will be asked in an exam, but it will help you to have an idea of what the cosine of an angle "tells us".

Tangent and what it actually means?

In this video I'll explain a little about what tangent is. This is not necessarily something that will be asked in an exam, but it will help you to have an idea of what the tangent of an angle "tells us"

How to remember what Trig ratios to use?

If you've never heard of SOH CAH TOA, then this is the place for you 🙂

Work out a side if an angle and side is given

In this video we do some examples using trig ratio's.

Work out a side if an angle and side is given - Part 2

In this video we do some examples using trig ratios.

Working out a side of a triangle that is a little rotated.

Not all triangles will be "nice" - some are rotated so it is important to name the sides of the triangle to know which ratio to use.

Know when to use a function or a rule.

In this video we look at some past paper examples to identify what trig function or rule we need to use to solve. In short you use Sin, Cos or Tan when you have a right angles triangle, but for other triangles you would use the Sine or Cosine rule. (Sine and Cosine rule for extended only)

Past Paper Questions - Coming Soon(ish)

Videos for extended work will be loaded here later.

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