Pre-Calculus 11 Notes

By: Gen L.

Lesson 1: Trigonometry (Grade 10 Review)

1.1: Pythagorean Theorem

The Pythagorean Theorem

• • Can be rewritten to find a specific side.
• • Square root both sides.

Example 1:

• For , solve for unknown side:
  • let
• • What can we use? The Pythagorean Theorem
• • Rewrite, then solve.

Example 2:

• For , solve for unknown side:
  • let

1.2: Trigonometric Ratios

Trigonometry Ratios

There are Three primary Trigonometric Ratios: Sine (), Cosine (), Tangent ().

Notational Notes:

Sine, Cosine & Tangent will be replaced with these operators:

• Sine:
• Cosine:
• Tangent:

This makes it clearer that it is an operator on the value in the parenthesis.

Ratios

We use the acronym SOH-CAH-TOA to help us remember.

Example 1:

• Find the missing sides or angles:

Example 2:

• • • both sides
  • • , so these cancel out.

Example 3:

• • • on both sides

Example 4:

• • • on both sides

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