MA16-07 Maths Coming soon

Solving Trigonometric Equations from a Graph

MA16-07

This lesson is coming soon.

Watch now instead: MA23-01 Perimeter of 2D and composite shapes

In this lesson

Solve trigonometric equations of the form sin x=k, cos x=k or tan x=k for a given domain, using the graph's symmetry to find every solution.

What it covers

Solving sin x=k, cos x=k, tan x=k for x within a stated domain, both graphically (reading crossing points off the curve) and algebraically (using the calculator's inverse function plus the curve's symmetry)
Using the shape of the relevant graph to find every solution in the domain, not just the calculator's single principal-value answer

Key words

solve trig equation sin x = k cos x = k tan x = k

For: Cambridge IGCSE 0580

On the specification

Board	Spec	Statement
Cambridge IGCSE 0580	E6.4	Trigonometric functions

For teachers

This GCSE Maths lesson teaches solving trigonometric equations from a graph. By the end, students should be able to solve trigonometric equations of the form sin x=k, cos x=k or tan x=k for a given domain, using the graph's symmetry to find every solution. It works through two worked examples and the mistakes examiners report.