nvec ← ##.roots triple ⍝ Real roots of quadratic. An illustration of a 'typical' D-function: roots←{ ⍝ Real roots of quadratic. a b c←⍵ ⍝ Coefficients. d←(b*2)-4×a×c ⍝ Discriminant. d<0:⍬ ⍝ No roots d=0:-b÷2×a ⍝ One root d>0:(-b+¯1 1×d*0.5)÷2×a ⍝ Two roots } NB: This function could be recoded so that it always returns two roots, each of which may be complex: roots←{ ⍝ Roots of quadratic. a b c←⍵ ⍝ coefficients. d←(b*2)-4×a×c ⍝ discriminant. (-b+¯1 1×d*0.5)÷2×a ⍝ both roots. } then roots 1 2 3 ¯1J1.414213562 ¯1J¯1.414213562 Example: roots 2 1 ¯3 1 ¯1.5 Back to: contents Back to: Workspaces