Respuesta :
Use a(n) = 10 as a starting point and create an equation:
a(n) = b * a(n-1)
10 = b * -5
b = -2
a(n) = b * a(n-1)
10 = b * -5
b = -2
Answer:
value of b = -2
Step-by-step explanation:
Consider the following geometric sequence -5, 10, -20, 40,..... if the recursive formula for the sequence above expressed in the form a(n)=b*a(n-1)
first we write the recursive formula for the given sequence
To get the recursive formula we find common ratio
Common ration = second term divide by first term
10/-5= -2
-20/ 10= -2
a(n)=common ratio *a(n-1)
a(n)=(-2)*a(n-1)
So b = -2