Working with Logarithms?

[Dillinger4]

Am i doing this correctly? 2⁴ = 16 --> log2⁽²⁾⁴ = log2¹⁶ --> 4 = log2¹⁶

And also i thought finding the root of a number was the inverse of an exponent? 5² = 25 --> Sqr(25) = 5