According to given expression:
[tex]y=\sec (\cot ^{-1}(-\frac{3}{4}))[/tex]First solve the inner bracket:
[tex]\begin{gathered} x=\cot ^{-1}(-\frac{3}{4}) \\ \cot (x)=-\frac{3}{4} \\ \tan (x)=-\frac{4}{3} \\ x=\tan ^{-1}(-\frac{4}{3}) \\ x=-53.06 \end{gathered}[/tex]Now put this value in above given expression:
[tex]\begin{gathered} y=\sec (-53.06) \\ y=\frac{1}{\cos (-53.06}) \\ y=\frac{1}{0.6009} \\ y=1.6640 \end{gathered}[/tex]So the value of given expression is 1.6640.