Question 1039871
{{{sec(x)=1/cos(x)}}} => {{{cos(x)=1/sec(x)}}}
{{{cos(x)=1/(13/5)=5/13}}}
{{{(sin(x))^2+(cos(x))^2=1}}}=> {{{(sin(x))^2=1-(cos(x))^2}}}
{{{(sin(x))^2=1-(5/13)^2=1-25/169=(169-25)/169=144/169}}}
{{{sin(x)=12/13}}}
Answer: B) {{{12/13}}}