Display $1$

$($a$)$ Choose the display that best demonstrates the identity $sin=cos(\frac{}{2}-).$

Display $1$

Display $2$

Display $3$

$($b$)$ Choose the display that best demonstrates the identity $cos=sin(\frac{}{2}+).$

$$ Display $1$ Display $2$

Display $3$

$($c$)$ Fill in the blank.

$sin(\frac{3}{14})=sin(-\frac{3}{14})$