If x, y, z are three consecutive positive integers, then log (1 + xz) is:
2023
If x, y, z are three consecutive positive integers, then log (1 + xz) is:
- A.
log y
- B.
log y/2
- C.
log (2y)
- D.
2 log (y)
Attempted by 2 students.
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Correct answer: D
Step-by-Step Solution
To simplify the expression log(1 + xz), we first express x and z in terms of y, given that x, y, and z are consecutive positive integers.
Express consecutive integers in terms of y:
Let the three consecutive integers be: x = y - 1 y = y z = y + 1
Simplify the expression inside the logarithm (1 + xz):
Substitute x = y - 1 and z = y + 1 into the expression 1 + xz: 1 + (y - 1)(y + 1)
Using the difference of squares formula, (y - 1)(y + 1) = y^2 - 1.
So, 1 + xz = 1 + (y^2 - 1)
1 + xz = y^2
Apply the logarithm:
The original expression is log(1 + xz).
Substituting our simplified result: log(y^2)
Using the logarithmic power rule, log(a^b) = b log(a), we can move the exponent 2 in front: 2 log(y)