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                                    If h = 1 then prove that (E-1 ∆) x3 = 3x2 – 3x + 1. | 
                            
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Answer»  h = 1 To prove (E-1 ∆) x3 = 3×2 – 3x + 1 L.H.S = (E-1 ∆) x3 = E-1 (∆x3 ) = E-1 [(x + h)3 – x3 ] = E-1 ( x + h)3 – E-1 (x3) = (x – h + h)3 – (x – h)3 = x3 (x – h)3 But given h = 1 So(E-1 ∆) x3 = x3 - (x – 1)3 = x3 – [x3 - 3x2 + 3x – 1] = 3x2 – 3x + 1 = RHS  | 
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