Wiskunde Multiple Choice Vraag uit Gricha's Wiskundige Vragenbank

− sin² 45° − cos² 45° is gelijk aan	A. 1
B. − 2
C. − 1
D. 0
E. − 1,5

− sin² 45° − cos² 45° is equal to	A. 1
B. − 2
C. − 1
D. 0
E. − 1.5

$https://latex.codecogs.com/png.image?\dpi{110}\\{\color{DarkGreen} 1^{ste}\;manier\;: }\\ -\sin^245^\circ -\cos^245^\circ = -\left ( \frac{\sqrt2}{2} \right )^2-\left ( \frac{\sqrt2}{2} \right )^2=-\frac24-\frac24=-\frac44=\cdots \\{\color{DarkGreen} 2^{de}\;manier\;: }\\-\sin^245^\circ -\cos^245^\circ = -2.\sin^245^\circ=-2\left ( \frac{\sqrt2}2 \right )^2=-2.\frac24=\cdots \\{\color{DarkGreen} 3^{de}\;manier\;: }\\-\sin^245^\circ -\cos^245^\circ = -(\sin^245^\circ +\cos^245^\circ)=-1$