Recitation 16 Solution d d 1 1+x+x2+x3+ 1+2x+3x2+4xr2+ 2 2+4x+6x2+8x2+ 1+3x+5x2+7x3+ (1-x)Recitation 16 2 Solution. 1 3 1 + x + x 2 + x + . . . = 1 − x d d 1 1 + x + x 2 + x 3 + . . . = dx dx 1 − x 1 2 1 + 2x + 3x 2 + 4x + . . . = (1 − x ) 2 2 2 2 + 4x + 6x 2 + 8x + . . . = (1 − x ) 2 2 1 3 1 + 3x + 5x 2 + 7x + . . . = (1 − x )2 − 1 − x 1 + x = (1 − x)2