Question

B4=8,b7=512,q=4,знайти b1​

Answer 1

Ответ:

$\frac{1}{8}$

Объяснение:

bn=b1*q^n-1

8=b1*(4)^3

b1=8/(4)^3=8/(64)=1/8.

Answer 2

To find the value of b1, we need to understand the pattern in the given values of b4, b7, and q.

Let's analyze the pattern:

1. b4 = 8
2. b7 = 512
3. q = 4

From the given information, it seems that each term (b1, b4, b7) is related by an exponential growth pattern, with a common ratio of q.

To find b1, we can use the formula for the nth term of a geometric sequence:

b_n = a * r^(n-1)

where: b_n is the nth term of the sequence. a is the first term (b1 in this case). r is the common ratio (q in this case). n is the position of the term we want to find.

Now, we have:

b4 = b1 * q^(4-1) b7 = b1 * q^(7-1)

We can use these two equations to solve for b1. Divide the two equations to eliminate b1:

b7 / b4 = (b1 * q^(7-1)) / (b1 * q^(4-1))

512 / 8 = q^(7-4)

64 = q^3

Now, we need to find the value of q. From the given information:

q = 4

Now, let's find b1:

b1 = b4 / q^(4-1) b1 = 8 / 4^3 b1 = 8 / 64 b1 = 1/8 b1 = 0.125

So, the value of b1 is 0.125.