Question 12
Indices and LogarithmsIf log10 y + 3 log10 x ≥ log10 x, express y in terms of x.
- A.y ≥ 1/x
- B.y ≤ 1/x
- C.y ≤ 1/x2
- D.y ≥ 1/x2
Show the answer and explanation
Answer: D (y ≥ 1/x2)
Explanation
log(x³y) ≥ log x, so x³y ≥ x and (x > 0) y ≥ 1/x².