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Use a half-angle identity to find the exact value of sinPi/8

User Nick Alger
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2 Answers

7 votes

Answer:

Explanation:

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Use a half-angle identity to find the exact value of sinPi/8-example-1
User Drsealks
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6 votes

Answer:

sin(π/8) = (1/2)√(2-√2)

Explanation:

Using the half-angle formula ...


\sin{(\theta)/(2)}=\sqrt{(1-cos(\theta))/(2)}

We can let θ = π/4 and simplify the result as follows:


\sin{(\pi)/(8)}=\sqrt{(1-cos((\pi/4)))/(2)}=\sqrt{(1-(√(2))/(2))/(2)}=\sqrt{(2-√(2))/(4)}\\\\=\boxed{(1)/(2)\sqrt{2-√(2)}}}

User Jason Scheirer
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4.9k points