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Induction (Reduction) Formula Calculator
Build expressions of the form ±α + k·π/2 and reduce sin/cos/tan using the parity and quadrant rules.
Function
sin
cos
tan
±α
+α
−α
k · π/2
−
+
α value (optional)
rad
deg
α is treated as acute for reduction. Numeric value is optional and for display only.
Standardized:
sin(α)
Name Rule:
sin → sin (k even)
Quadrant:
QI
Result:
sin(α)
Steps:
Original: sin(±α + k·π/2) with sign + and k = 0
Rule: k even → name unchanged (sin → sin)
Quadrant analysis: θ in QI
Sign by quadrant for original sin: +
Standardized angle: α
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