Question 948759
a) No solution, {{{abs(sin(t))<=1}}}
b) No solution, {{{abs(cos(t))<=1}}}
c) I think you mean ,
{{{tan(t)=sqrt(13)}}}
{{{t=74.4986}}} and {{{t=254.4986}}} {{{degrees}}} 
{{{t=1.30}}} and {{{t=4.44}}} {{{radians}}}