Getal & Ruimte (13e editie) - vwo wiskunde B
'Sinus, cosinus en tangens'.
| 3 vwo | 6.3 Berekeningen met de tangens |
opgave 13p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=21\text{,}\) \(\angle A=42\degree\) en \(\angle B=90\degree\text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle A)={B\kern{-.8pt}C \over A\kern{-.8pt}B}\) ofwel \(\tan(42\degree)={B\kern{-.8pt}C \over 21}\text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C=21⋅\tan(42\degree)\text{.}\) 1p ○ Dus \(B\kern{-.8pt}C≈18{,}9\text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=37\text{,}\) \(\angle Q=47\degree\) en \(\angle R=90\degree\text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle Q)={P\kern{-.8pt}R \over Q\kern{-.8pt}R}\) ofwel \(\tan(47\degree)={37 \over Q\kern{-.8pt}R}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R={37 \over \tan(47\degree)}\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈34{,}5\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=31\text{,}\) \(P\kern{-.8pt}Q=29\) en \(\angle P=90\degree\text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle R)={P\kern{-.8pt}Q \over P\kern{-.8pt}R}\) ofwel \(\tan(\angle R)={29 \over 31}\text{.}\) 1p ○ Hieruit volgt \(\angle R=\tan^{-1}({29 \over 31})\text{.}\) 1p ○ Dus \(\angle R≈43{,}1\degree\text{.}\) 1p |
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| 3 vwo | 6.4 De sinus en de cosinus |
opgave 13p a Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=52\text{,}\) \(\angle L=41\degree\) en \(\angle M=90\degree\text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\sin(\angle L)={K\kern{-.8pt}M \over K\kern{-.8pt}L}\) ofwel \(\sin(41\degree)={K\kern{-.8pt}M \over 52}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}M=52⋅\sin(41\degree)\text{.}\) 1p ○ Dus \(K\kern{-.8pt}M≈34{,}1\text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R=48\text{,}\) \(\angle P=34\degree\) en \(\angle Q=90\degree\text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle P)={Q\kern{-.8pt}R \over P\kern{-.8pt}R}\) ofwel \(\sin(34\degree)={48 \over P\kern{-.8pt}R}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}R={48 \over \sin(34\degree)}\text{.}\) 1p ○ Dus \(P\kern{-.8pt}R≈85{,}8\text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=60\text{,}\) \(A\kern{-.8pt}B=75\) en \(\angle C=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle B)={A\kern{-.8pt}C \over A\kern{-.8pt}B}\) ofwel \(\sin(\angle B)={60 \over 75}\text{.}\) 1p ○ Hieruit volgt \(\angle B=\sin^{-1}({60 \over 75})\text{.}\) 1p ○ Dus \(\angle B≈53{,}1\degree\text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=73\text{,}\) \(\angle P=57\degree\) 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 \(\cos(57\degree)={P\kern{-.8pt}Q \over 73}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q=73⋅\cos(57\degree)\text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q≈39{,}8\text{.}\) 1p opgave 23p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R=24\text{,}\) \(\angle Q=47\degree\) en \(\angle R=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\cos(\angle Q)={Q\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\cos(47\degree)={24 \over P\kern{-.8pt}Q}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q={24 \over \cos(47\degree)}\text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q≈35{,}2\text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R=57\text{,}\) \(P\kern{-.8pt}Q=78\) en \(\angle R=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 0ms b Cosinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\cos(\angle Q)={Q\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\cos(\angle Q)={57 \over 78}\text{.}\) 1p ○ Hieruit volgt \(\angle Q=\cos^{-1}({57 \over 78})\text{.}\) 1p ○ Dus \(\angle Q≈43{,}0\degree\text{.}\) 1p |