Wiskunde Multiple Choice Vraag uit Gricha's Wiskundige Vragenbank

sin 70° cos 70° ——— + ———— sin 20° cos 20° is gelijk aan	A. 1
B. 2
C. ²/_{sin 40°}
D. ^{sin 40°}/₂
E. 2.tan 50°

sin 70° cos 70° ——— + ——— = sin 20° cos 20°	A. 1
	B. 2
	C. ²/_{sin 40°}
	D. ^{sin 40°}/₂
	E. 2.tan 50°

$https://latex.codecogs.com/png.image?\dpi{110}\inline\\\frac{\sin70^\circ}{\sin20^\circ}+\frac{\cos70^\circ}{\cos20^\circ}=\frac{\cos20^\circ}{\sin20^\circ}+\frac{\sin20^\circ}{\cos20^\circ}=\frac{\cos^220^\circ+\sin^220^\circ}{\sin20^\circ\cdot \cos20^\circ}\\{\color{Green} .\qquad\qquad\qquad\quad}=\frac{1}{\frac12.2.\sin20^\circ.\cos20^\circ}=\frac{2}{\sin 40^\circ}$