إذا كانت f (1) = 3 و f (n) = -2f (n-1) + 1 ، فما هو f (5)؟

إجابة:

# F (5) = 43 #

تفسير:

# F (1) = 3 #

# F (ن) = - 2F (ن 1) + 1 #

# F (2) = - 2F (1) + 1 #

# F (2) = - 2 (3) + 1 = -6 + 2 = -5 #

# F (3) = - 2F (2) + 1 #

# F (3) = - 2 (-5) + 1 #

# F (3) = 11 #

# F (4) = - 2 (و) 3 () + 1 #

# F (4) = - 2 (11) + 1 #

# F (4) = - 22 + 1 = -21 #

# F (5) = - 2 (و (4)) + 1 #

# F (5) = - 2 (-21) + 1 #

# F (5) = 42 + 1 #

# F (5) = 43 #