AB stel 'n vertikale netbalpaal voor - NSC Mathematics - Question 7 - 2017 - Paper 2
Question 7
AB stel 'n vertikale netbalpaal voor. Twee spelers word aan weerskante van die netbalpaal by punt D en E geplaas sodanig dat B, E en D op dieselfde regu lijn is. 'n ... show full transcript
Worked Solution & Example Answer:AB stel 'n vertikale netbalpaal voor - NSC Mathematics - Question 7 - 2017 - Paper 2
Step 1
Skryf die grootte van ABC neer.
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Answer
In
triangle ABC, die hoek
ABC is regtehoekig, dus:
[ \angle ABC = 90^\circ ]
Step 2
Toon dat AC = \( \frac{k \cdot tan y}{sin x} \).
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Answer
In
triangle ABE:
AB = k \cdot tan y
BE = tan y
AB = k \cdot tan y
In
triangle ABC:
AB = k \cdot tan y
AC = sin x
Derde stap:
[ AC = \frac{AB \cdot sin x}{tan y} ]
Substituer met AB:
[ AC = \frac{k \cdot tan y \cdot sin x}{tan y} = \frac{k \cdot tan y}{sin x} ]
Step 3
Indien dit verder gegee word dat DAC = 2x en AD = AC = AC, toon dat 2k tan y die afstand DC tussen die spelers by D en C is.
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Answer
Laat ons die sine-reël gebruik:
[ \frac{DC}{sin(90 - x)} = \frac{AC}{sin x} ]
Hieruit volg:
[ DC = \frac{AC \cdot sin(90 - x)}{sin x} ]
Simplifisering:
[ DC = \frac{AC \cdot cos x}{sin x} ]
Substitueer AC:
[ DC = \frac{k tan y \cdot cos x}{sin x} = 2k tan y ]