а) 48, 12,...
b1 = 48, q = 1/4
b6 = b1*q^5 = 48/4^5 = 3/64
bn = b1*q^(n-1) = 48/4^(n-1) = 3*(4^(3-n))
б) 64/9, -32/3...
b1 = 64/9, q = - 3/2
b6 = b1*q^5 = - 64*243/(9*32) = -54
bn = b1*q^(n-1) = (64/9)*(-3/2)^(n-1)
в) -0,001; -0,01...
b1 = -0,001; q = 10
b6 = b1*q^5 = -0,001*10^5 = -100
bn = b1*q^(n-1)= -0,001* 10^(n-1) = -10^(n-4)
г) -100, 10....
b1= -100; q = -0,1
b6 = b1*q^5 = 100 *(-10)^(-5) = -0,001
bn = b1*q^(n-1) = 100*(-0,1)^(n-1)