Hallo,
zum Schluß noch die Grenzen einsetzen:
\( \begin{array}{rl}{\int \sqrt{1-x^{2}} d x} & {x=\sin (z)} \\ {\frac{d x}{a z}} & {=\cos (z)} \\ {d x} & {=\cos (z) d z}\end{array} \)
\( =\int \sqrt{1-\sin ^{2}(z)} \quad \cos (z) d z \)
\( =\int \sqrt{\cos^2(z)} \cdot \cos (z) d z \)
\( =\int \cos ^{2}(z) d z \)
\( \cos ^{2}(z)=\frac{1}{2}(\cos (2 z)+1)) \)
\( =\frac{1}{2} \int \cos (2 z) d z+\frac{1}{2} \int 1 d t \)
\( =\frac{1}{2} \cdot \sin (z) \cos (z)+\frac{1}{2} z+c=>Resubstitution =\frac{1}{2} \sqrt{1-x^{2}} x+\frac{1}{2} \arcsin (x)+c \)