Use a calculator to calculate the values of the expressions.

a) [[$ \displaystyle\frac {\sin 37° - \cos 37°} {\sin 14° + 2 \cdot \cos 5°} ≈ $]]

b) [[$ \displaystyle\frac {5 \cdot \sin 11° - \sin \; \left ( 3 \cdot 10°\right )} {\cos 0°} ≈ $]]

c) [[$ \sin 4° \cdot (22.5 + \cos 55° ) ≈ $]]