Pre-Calculus 12 Notes

By: Gen L.

Lesson 3: Trigonometric Ratios

Trig Ratios

In general, for the trig ratios:

Trig Ratios (Unit Circle)

For the Unit circle:

Angle - Point Ratios

• The terminal arm of passes through the point . Find the exact six trig ratios.

Angle - Point Ratios, cont

For this, I don't recommend rationalising the denominator.

Find Other Ratios

If and , find the other 5 ratios

Searching Ratios

Reference Angles

Measure of angles to nearest -axis.

is dependant on the quadrant

• :
• :
• :
• :

Reference Angles (Deg)

Find for and .

Determining Reference Angles (rad)

Find for and .

1. Common Denominator
2. Reduction to within
3. Determine Reference Angle.

Reference Angles (rad)

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