Find the first four terms in the sequence.
an=-a n-1 +7 a1=2
huh? Just start plugging in values for n: 1,2,3,4,...
a1 = 2
a2 = -a1+7 = -2+7 = 5
a3 = -a2+7 = ...
and so on
note that a_(n+1) = -a_n + 7 = -(-a_(n-1) + 7) + 7 = a_(n-1)
an=-a n-1 +7 a1=2
a1 = 2
a2 = -a1+7 = -2+7 = 5
a3 = -a2+7 = ...
and so on
note that a_(n+1) = -a_n + 7 = -(-a_(n-1) + 7) + 7 = a_(n-1)