Consider the two values:

A = 2^2^2^83
and B = 3^3^3^53
Because these two numbers are so large, we cannot directly compare them. Compute ln(ln(A)) and ln(ln(B)) to determine whether A > B or A < B. Explain how you used the values of ln(ln(A)) and ln(ln(B)) to determine your answer and explain why your method is valid.

1 answer

To compare the values A and B, we can compute ln(ln(A)) and ln(ln(B)) and then compare these logarithmic values instead.

First, let's compute ln(A) and ln(B):

ln(A) = ln(2^2^2^83)
= ln(2^2^2^82 * 2^2^2^82)
= ln(2^2^2^82) + ln(2^2^2^82)
= 2^2^82 * ln(2) + 2^2^82 * ln(2)
= 4^2^82 * ln(2)

Similarly,

ln(B) = ln(3^3^3^53)
= ln(3^3^3^52 * 3^3^3^52)
= ln(3^3^3^52) + ln(3^3^3^52)
= 3^3^3^52 * ln(3) + 3^3^3^52 * ln(3)
= 9^3^3^52 * ln(3)

Now, let's compute ln(ln(A)) and ln(ln(B)):

ln(ln(A)) = ln(ln(4^2^82 * ln(2)))
= ln(2^2^82 * ln(ln(2)))
= 2^2^82 * ln(ln(2)) + 2^2^82 * ln(ln(2))
= 4^2^82 * ln(ln(2))

ln(ln(B)) = ln(ln(9^3^3^52 * ln(3)))
= ln(3^3^3^52 * ln(ln(3)))
= 3^3^3^52 * ln(ln(3)) + 3^3^3^52 * ln(ln(3))
= 9^3^3^52 * ln(ln(3))

Now, we can compare ln(ln(A)) and ln(ln(B)).

Since 4^2^82 > 3^3^3^52 and ln(x) is an increasing function, we know that ln(ln(4^2^82 * ln(2))) > ln(ln(3^3^3^52 * ln(3))). Therefore, ln(ln(A)) > ln(ln(B)).

This implies that A > B, as ln(ln(A)) is greater than ln(ln(B)).

This method is valid because logarithmic functions are monotonic, meaning if a > b, then ln(a) > ln(b). By comparing the logarithmic values, we are essentially comparing the exponents and logarithms used in the calculations of A and B, allowing us to determine the relationship between the two large values.