Trigonometryy (1 Viewer)

coyazayo · Jul 14, 2016

Find the exact value of tan22.5 degrees by using the expression for tan2x

Thanks in advance

Drongoski · Jul 14, 2016

$tan 45^\circ = tan(2 \times 22.5^\circ) = \frac {2 \times tan 22.5^\circ } {1 - tan^2 22.5^\circ} = 1 = \frac {2m}{1 - m^2}$

Just solve the quadratic equation in m, viz 1 - m² = 2m, choosing the correct value.

Trigonometryy (1 Viewer)

coyazayo

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Drongoski

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