Question

Why k mustn't be equal to 1 to use this formula? `int1/sqrt(x^2 + k) = ln|x + sqrt(x^2 + k)|`

Answer 1

`"k can be equal to 1 without a problem"`

Explanation:

`"If we derive the RHS for k = 1 we get LHS as should :"`

`(1 + (2x)/(2 sqrt(x^2 + k)))/(x + sqrt(x^2 + k))`

`= ((2 sqrt(x^2 + k) + 2x)/(2 sqrt(x^2 + k)))/(x + sqrt(x^2+k))`

`= ((sqrt(x^2 + k) + x)/sqrt(x^2 + k))/(x + sqrt(x^2 + k))`

`= 1 / sqrt(x^2 + k)`