documentclass[tikz,border=3.14mm]{standalone}
usepackage{pgfplots}
pgfplotsset{compat=1.16}
begin{document}

begin{tikzpicture}[declare function={f(x)=1/(sqrt(1-x*x));}]
begin{axis}[samples=101,
    xlabel=$x$,ylabel=$y$,
    ymax=10, ymin=-1, xmin=0, xmax=1,
    domain=0:1,
    ]
  addplot [mark=none,smooth] {f(x)};
  addlegendentry{$1/sqrt{1-x^2}$}
  addplot+ [mark=none,smooth] {asin(x)*pi/180};
  addlegendentry{$arcsin(x)$}
end{axis}
end{tikzpicture}
end{document}