Getal & Ruimte (13e editie) - havo wiskunde B
'Sinus, cosinus en tangens'.
| 3 havo | 6.3 Berekeningen met de tangens |
opgave 13p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 38 \text{,}\) \(\angle C = 56\degree\) en \(\angle A = 90\degree \text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle C) = {A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\tan(56\degree) = {A\kern{-.8pt}B \over 38} \text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B = 38 ⋅ \tan(56\degree) \text{.}\) 1p ○ Dus \(A\kern{-.8pt}B ≈ 56{,}3 \text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M = 58 \text{,}\) \(\angle L = 57\degree\) en \(\angle M = 90\degree \text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\tan(\angle L) = {K\kern{-.8pt}M \over L\kern{-.8pt}M}\) ofwel \(\tan(57\degree) = {58 \over L\kern{-.8pt}M} \text{.}\) 1p ○ Hieruit volgt \(L\kern{-.8pt}M = {58 \over \tan(57\degree)} \text{.}\) 1p ○ Dus \(L\kern{-.8pt}M ≈ 37{,}7 \text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 46 \text{,}\) \(A\kern{-.8pt}B = 34\) 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 \(\tan(\angle C) = {34 \over 46} \text{.}\) 1p ○ Hieruit volgt \(\angle C = \tan^{-1}({34 \over 46}) \text{.}\) 1p ○ Dus \(\angle C ≈ 36{,}5\degree \text{.}\) 1p |
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| 3 havo | 6.4 De sinus en de cosinus |
opgave 13p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R = 53 \text{,}\) \(\angle R = 47\degree\) en \(\angle P = 90\degree \text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle R) = {P\kern{-.8pt}Q \over Q\kern{-.8pt}R}\) ofwel \(\sin(47\degree) = {P\kern{-.8pt}Q \over 53} \text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q = 53 ⋅ \sin(47\degree) \text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q ≈ 38{,}8 \text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q = 23 \text{,}\) \(\angle R = 40\degree\) en \(\angle P = 90\degree \text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle R) = {P\kern{-.8pt}Q \over Q\kern{-.8pt}R}\) ofwel \(\sin(40\degree) = {23 \over Q\kern{-.8pt}R} \text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R = {23 \over \sin(40\degree)} \text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R ≈ 35{,}8 \text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R = 48 \text{,}\) \(P\kern{-.8pt}R = 55\) en \(\angle Q = 90\degree \text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle P) = {Q\kern{-.8pt}R \over P\kern{-.8pt}R}\) ofwel \(\sin(\angle P) = {48 \over 55} \text{.}\) 1p ○ Hieruit volgt \(\angle P = \sin^{-1}({48 \over 55}) \text{.}\) 1p ○ Dus \(\angle P ≈ 60{,}8\degree \text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R = 80 \text{,}\) \(\angle P = 51\degree\) en \(\angle Q = 90\degree \text{.}\) Cosinus (1) 007j - Sinus, cosinus en tangens - basis - 0ms d Cosinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\cos(\angle P) = {P\kern{-.8pt}Q \over P\kern{-.8pt}R}\) ofwel \(\cos(51\degree) = {P\kern{-.8pt}Q \over 80} \text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q = 80 ⋅ \cos(51\degree) \text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q ≈ 50{,}3 \text{.}\) 1p opgave 23p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C = 22 \text{,}\) \(\angle C = 31\degree\) 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 \(\cos(31\degree) = {22 \over B\kern{-.8pt}C} \text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C = {22 \over \cos(31\degree)} \text{.}\) 1p ○ Dus \(B\kern{-.8pt}C ≈ 25{,}7 \text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L = 45 \text{,}\) \(K\kern{-.8pt}M = 50\) 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 \(\cos(\angle K) = {45 \over 50} \text{.}\) 1p ○ Hieruit volgt \(\angle K = \cos^{-1}({45 \over 50}) \text{.}\) 1p ○ Dus \(\angle K ≈ 25{,}8\degree \text{.}\) 1p |