UCSS Math II 5.9.4 Example 1

Prove the Pythagorean identity sin cos.
  1. Draw a labeled diagram of a right triangle.
  2. Apply the Pythagorean Theorem to this triangle.
  3. Divide both sides of this equation by .
  4. Rewrite this equation using the laws of exponents.
  5. Find sin and cos by looking at the diagram.
  6. Substitute sin and cos into the equation from step 4.
  7. Rewrite the equation using the standard notation for trigonometric functions with exponents.
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