Answer:
-1.29897714066
Step-by-step explanation:
see explanation
cos90° - sin45°
= 0 - [tex]\frac{\sqrt{2} }{2}[/tex] ( exact value of sin45° )
= - [tex]\frac{\sqrt{2} }{2}[/tex]
≈ - 0.707 ( to 3 dec. places )
