Question

Which expression represents the value of sin C - cos C?r + sr- sr/ss- r

Answer 1

The sum of angle of triangle is equal to 180 degree. So equation for angle B and angle C is,

$\begin{gathered} B+C+90=180 \\ B=90-C \end{gathered}$

Substitute 90 - C for B in the expression to obtain the value of sin C and cos C.

$\begin{gathered} \sin B=r \\ \sin (90-C)=r \\ \cos C=r \end{gathered}$

And

$\begin{gathered} \cos B=s \\ \cos (90-C)=s \\ \sin C=s \end{gathered}$

Evaluate the value of sinC - cosC.

$\sin C-\cos C=s-r$

So answer is s -r.