trigonometry · worked example

Solve sin(45°)

Method: special angle. Verified step-by-step solution with our free AI math solver.
Problem

sin(45°)\sin(45°)

Step-by-step solution

  1. In a 4545-4545-9090 isosceles right triangle, opposite leg / hypotenuse = 12\frac{1}{\sqrt{2}}.

  2. Rationalise: 1222=22\frac{1}{\sqrt{2}} \cdot \frac{\sqrt{2}}{\sqrt{2}} = \frac{\sqrt{2}}{2}.

  3. On the unit circle at 45°45° both x and y equal 22\frac{\sqrt{2}}{2} — confirms the answer.

Answer

sin(45°)=22\sin(45°) = \tfrac{\sqrt{2}}{2}

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