How many of the following integrals are correct? 1. ∫dx√x2+a2=ln|x+√x2+a2|+C 2. ∫dx√x2−a2=ln|x−√x2−a2|+C 3. ∫dxx2−a2=12aln∣∣x−ax+a∣∣+C 4. ∫dxa2−x2=12aln∣∣x+ax−a∣∣+C___

How many of the following integrals are correct? 1. ∫dx√x2+a2=ln|x

1.	How many of the following integrals are correct? 1. ∫dx√x2+a2=ln\|x+√x2+a2\|+C 2. ∫dx√x2−a2=ln\|x−√x2−a2\|+C 3. ∫dxx2−a2=12aln∣∣x−ax+a∣∣+C 4. ∫dxa2−x2=12aln∣∣x+ax−a∣∣+C___
Answer» How many of the following integrals are correct? 1. $\int \frac{d x}{\sqrt{x^{2} + a^{2}}} = l n \| x + \sqrt{x^{2} + a^{2}} \| + C$ 2. $\int \frac{d x}{\sqrt{x^{2} - a^{2}}} = l n \| x - \sqrt{x^{2} - a^{2}} \| + C$ 3. $\int \frac{d x}{x^{2} - a^{2}} = \frac{1}{2 a} l n ∣ ∣ \frac{x - a}{x + a} ∣ ∣ + C$ 4. $\int \frac{d x}{a^{2} - x^{2}} = \frac{1}{2 a} l n ∣ ∣ \frac{x + a}{x - a} ∣ ∣ + C$ ___