Question 1195257
a.
 {{{sin^-1 (-1)}}}

use the property {{{sin^-1(-1)=  -sin^-1(1)}}}

The range of arcsin is defined as between  {{{-pi/2}}}  radians and {{{pi/2}}} radians.

 {{{sin^-1 (-1)= -sin^-1 (1)=-pi/2}}}
 

b. 

{{{tan^-1 (-1)}}}


Use the following property:  {{{tan^-1(-x)= -tan^-1(x)}}}

{{{-tan^-1 (1)=-pi/4}}}