[tex]\bf sin(-t)=\cfrac{5}{7}\implies -sin(t)=\cfrac{5}{7}\implies sin(t)=-\cfrac{5}{7}\\\\
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csc(t)\implies \cfrac{1}{sin(t)}\implies \cfrac{1}{-\frac{5}{7}}\implies \cfrac{\frac{1}{1}}{-\frac{5}{7}}\implies \cfrac{1}{1}\cdot -\cfrac{7}{5}\implies -\cfrac{7}{5}[/tex]
