Getal & Ruimte (13e editie) - 3 vwo
'Sinus, cosinus en tangens'.
| 3 vwo | 6.3 Berekeningen met de tangens |
opgave 13p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R = 58 \text{,}\) \(\angle R = 42\degree\) en \(\angle P = 90\degree \text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle R) = {P\kern{-.8pt}Q \over P\kern{-.8pt}R}\) ofwel \(\tan(42\degree) = {P\kern{-.8pt}Q \over 58} \text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q = 58 ⋅ \tan(42\degree) \text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q ≈ 52{,}2 \text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R = 21 \text{,}\) \(\angle P = 43\degree\) en \(\angle Q = 90\degree \text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle P) = {Q\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\tan(43\degree) = {21 \over P\kern{-.8pt}Q} \text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q = {21 \over \tan(43\degree)} \text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q ≈ 22{,}5 \text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 53 \text{,}\) \(A\kern{-.8pt}B = 58\) en \(\angle A = 90\degree \text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle C) = {A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\tan(\angle C) = {58 \over 53} \text{.}\) 1p ○ Hieruit volgt \(\angle C = \tan^{-1}({58 \over 53}) \text{.}\) 1p ○ Dus \(\angle C ≈ 47{,}6\degree \text{.}\) 1p |
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| 3 vwo | 6.4 De sinus en de cosinus |
opgave 13p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 72 \text{,}\) \(\angle A = 37\degree\) en \(\angle B = 90\degree \text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle A) = {B\kern{-.8pt}C \over A\kern{-.8pt}C}\) ofwel \(\sin(37\degree) = {B\kern{-.8pt}C \over 72} \text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C = 72 ⋅ \sin(37\degree) \text{.}\) 1p ○ Dus \(B\kern{-.8pt}C ≈ 43{,}3 \text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B = 58 \text{,}\) \(\angle C = 31\degree\) en \(\angle A = 90\degree \text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle C) = {A\kern{-.8pt}B \over B\kern{-.8pt}C}\) ofwel \(\sin(31\degree) = {58 \over B\kern{-.8pt}C} \text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C = {58 \over \sin(31\degree)} \text{.}\) 1p ○ Dus \(B\kern{-.8pt}C ≈ 112{,}6 \text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(B\kern{-.8pt}C = 33 \text{,}\) \(A\kern{-.8pt}C = 67\) en \(\angle B = 90\degree \text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle A) = {B\kern{-.8pt}C \over A\kern{-.8pt}C}\) ofwel \(\sin(\angle A) = {33 \over 67} \text{.}\) 1p ○ Hieruit volgt \(\angle A = \sin^{-1}({33 \over 67}) \text{.}\) 1p ○ Dus \(\angle A ≈ 29{,}5\degree \text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q = 57 \text{,}\) \(\angle Q = 55\degree\) en \(\angle R = 90\degree \text{.}\) Cosinus (1) 007j - Sinus, cosinus en tangens - basis - 0ms d Cosinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\cos(\angle Q) = {Q\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\cos(55\degree) = {Q\kern{-.8pt}R \over 57} \text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R = 57 ⋅ \cos(55\degree) \text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R ≈ 32{,}7 \text{.}\) 1p opgave 23p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 37 \text{,}\) \(\angle C = 46\degree\) en \(\angle A = 90\degree \text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle C) = {A\kern{-.8pt}C \over B\kern{-.8pt}C}\) ofwel \(\cos(46\degree) = {37 \over B\kern{-.8pt}C} \text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C = {37 \over \cos(46\degree)} \text{.}\) 1p ○ Dus \(B\kern{-.8pt}C ≈ 53{,}3 \text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L = 46 \text{,}\) \(K\kern{-.8pt}M = 67\) en \(\angle L = 90\degree \text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 0ms b Cosinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\cos(\angle K) = {K\kern{-.8pt}L \over K\kern{-.8pt}M}\) ofwel \(\cos(\angle K) = {46 \over 67} \text{.}\) 1p ○ Hieruit volgt \(\angle K = \cos^{-1}({46 \over 67}) \text{.}\) 1p ○ Dus \(\angle K ≈ 46{,}6\degree \text{.}\) 1p |