Overview
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Knowledge of set values of trigonometric functions
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Trigonometry in Triangles
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Sketching Trigonometric Functions
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Trigonometric Identities
Knowledge of set values of trigonometric functions
There are some common values of sinθ, cosθ and tanθ that should be known from memory.
These are:
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Trigonometry in Triangles
The three trigonometric equations for triangles:
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1. Sine Rule
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2. Cosine Rule
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​3. Area of a triangle
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Practice Questions:
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​2.
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Solutions:
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b.
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2.
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Sketching Trigonometric Functions
We need to be able to sketch y= sinθ, y = cosθ and y = tanθ;
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y= sinθ
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y = cosθ
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y = tanθ
Trigonometric Identities
Use of trigonometric identities:
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In order to solve trigonometric equations we need to use trigonometric identities
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The identities we need to be familiar with are:
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These will be necessary to solve an trigonometric equations
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For example:
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Here we can see that if we divide by cos x on both side we can get tan x = 2
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Now we can use inverse tan in order to find x
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However, we need to remember that there are multiple solutions to x at tan x = 2 for 0 < x < 360
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Therefore, we have 1 more solution and we must add 180o to the previous answer
Practice Questions:
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Solutions:
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