√2 + √2² + √2³ + .. + √2¹⁰ =
= √2 + 2 + 2√2 + 4 + 4√2 + 8 + 8√2 + 16 + 16√2 + 32
= (2 + 4 + 8 + 16 + 32) + (√2 + 2√2 + 4√2 + 8√2 + 16√2)
= 62 + 31√2
= 31(√2 + 2)
1 + 3 + .. + 2n - 1 = n²
2n - 1 = 2011 => 2n = 2012 => n = 1006
√(1 + 3 + .. + 2011) = √1006² = 1006