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 \(A\kern{-.8pt}C=55\text{,}\) \(\angle C=44\degree\) 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 \(\tan(44\degree)={A\kern{-.8pt}B \over 55}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B=55⋅\tan(44\degree)\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈53{,}1\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=29\text{,}\) \(\angle M=50\degree\) en \(\angle K=90\degree\text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\tan(\angle M)={K\kern{-.8pt}L \over K\kern{-.8pt}M}\) ofwel \(\tan(50\degree)={29 \over K\kern{-.8pt}M}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}M={29 \over \tan(50\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}M≈24{,}3\text{.}\) 1p 3p c Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=37\text{,}\) \(K\kern{-.8pt}L=43\) en \(\angle K=90\degree\text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\tan(\angle M)={K\kern{-.8pt}L \over K\kern{-.8pt}M}\) ofwel \(\tan(\angle M)={43 \over 37}\text{.}\) 1p ○ Hieruit volgt \(\angle M=\tan^{-1}({43 \over 37})\text{.}\) 1p ○ Dus \(\angle M≈49{,}3\degree\text{.}\) 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 \(A\kern{-.8pt}C=77\text{,}\) \(\angle A=32\degree\) 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 \(\sin(32\degree)={B\kern{-.8pt}C \over 77}\text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C=77⋅\sin(32\degree)\text{.}\) 1p ○ Dus \(B\kern{-.8pt}C≈40{,}8\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=31\text{,}\) \(\angle B=53\degree\) en \(\angle C=90\degree\text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle B)={A\kern{-.8pt}C \over A\kern{-.8pt}B}\) ofwel \(\sin(53\degree)={31 \over A\kern{-.8pt}B}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B={31 \over \sin(53\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈38{,}8\text{.}\) 1p 3p c Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=23\text{,}\) \(K\kern{-.8pt}L=38\) en \(\angle M=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\sin(\angle L)={K\kern{-.8pt}M \over K\kern{-.8pt}L}\) ofwel \(\sin(\angle L)={23 \over 38}\text{.}\) 1p ○ Hieruit volgt \(\angle L=\sin^{-1}({23 \over 38})\text{.}\) 1p ○ Dus \(\angle L≈37{,}2\degree\text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q=65\text{,}\) \(\angle Q=53\degree\) 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 \(\cos(53\degree)={Q\kern{-.8pt}R \over 65}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R=65⋅\cos(53\degree)\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈39{,}1\text{.}\) 1p opgave 23p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=39\text{,}\) \(\angle R=58\degree\) en \(\angle P=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\cos(\angle R)={P\kern{-.8pt}R \over Q\kern{-.8pt}R}\) ofwel \(\cos(58\degree)={39 \over Q\kern{-.8pt}R}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R={39 \over \cos(58\degree)}\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈73{,}6\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=44\text{,}\) \(A\kern{-.8pt}C=70\) en \(\angle B=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 0ms b Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle A)={A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\cos(\angle A)={44 \over 70}\text{.}\) 1p ○ Hieruit volgt \(\angle A=\cos^{-1}({44 \over 70})\text{.}\) 1p ○ Dus \(\angle A≈51{,}1\degree\text{.}\) 1p |