An alternating series is a summation with a sign change between terms: AltSeries((a_o, ..., a_4, a_5)) = a_0 - a_1 + a_2 - a_3 + a_4 - a_5 AltSeries((a_0, a_1, ..., a_n)) = summation_i = 0^n (-1)^i a^i Write a Haskell function called altSeries that computes an alternating series of an input list. altSeries :: Num a => [a] -> a An alternating series is a summation with a sign change between terms: AltSeries((a_o, ..., a_4, a_5)) = a_0 - a_1 + a_2 - a_3 + a_4 - a_5 AltSeries((a_0, a_1, ..., a_n)) = summation_i = 0^n (-1)^i a^i Write a Haskell function called altSeries that computes an alternating series of an input list. altSeries :: Num a => [a] -> a