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This applies to rules with a P scale.
To find the value of Ö(1-x2):
This scale can be used either for right angled triangles or for converting sin to cos (and vice versa).
For right angled triangles, c2 = b2 - a2
c = b Ö(1- (a/b)2 )
b=5.0 and a = 3.0 How long is c
Calculate a/b = 3.0/5.0 = 0.6
Cursor to 0.6 of Pythagorean scale (marked Ö(1-s2) and highlighted in green.)
10 on C to cursor,
Answer (4.0) under 5.0 on D.
For cosine the formula is:
cos = Ö(1- sin2)
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