Question

How do you solve `ln (1/e^5)=x`?

Answer 1

The soln. is # : x=-5

Explanation:

`ln(1/e^5)=x`

We know that, `1/e^a=e^(-a), and, lne^b=b`

`:. ln(e^(-5))=ln (e^x))............(1)`

Now, `ln` fun. is `1-1`. Hence, `(1) rArre^(-5)=e^x`.

Again, fun. `e^x` is `1-1`, so, `x=-5` is the soln.