Getal & Ruimte (12e 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 \(A\kern{-.8pt}B=27\text{,}\) \(\angle A=34\degree\) 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 \(\tan(34\degree)={B\kern{-.8pt}C \over 27}\text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C=27⋅\tan(34\degree)\text{.}\) 1p ○ Dus \(B\kern{-.8pt}C≈18{,}2\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=50\text{,}\) \(\angle L=35\degree\) 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 \(\tan(35\degree)={50 \over L\kern{-.8pt}M}\text{.}\) 1p ○ Hieruit volgt \(L\kern{-.8pt}M={50 \over \tan(35\degree)}\text{.}\) 1p ○ Dus \(L\kern{-.8pt}M≈71{,}4\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q=48\text{,}\) \(Q\kern{-.8pt}R=49\) en \(\angle Q=90\degree\text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle P)={Q\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\tan(\angle P)={49 \over 48}\text{.}\) 1p ○ Hieruit volgt \(\angle P=\tan^{-1}({49 \over 48})\text{.}\) 1p ○ Dus \(\angle P≈45{,}6\degree\text{.}\) 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 \(L\kern{-.8pt}M=77\text{,}\) \(\angle M=58\degree\) en \(\angle K=90\degree\text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\sin(\angle M)={K\kern{-.8pt}L \over L\kern{-.8pt}M}\) ofwel \(\sin(58\degree)={K\kern{-.8pt}L \over 77}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}L=77⋅\sin(58\degree)\text{.}\) 1p ○ Dus \(K\kern{-.8pt}L≈65{,}3\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(B\kern{-.8pt}C=54\text{,}\) \(\angle A=51\degree\) en \(\angle B=90\degree\text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle A)={B\kern{-.8pt}C \over A\kern{-.8pt}C}\) ofwel \(\sin(51\degree)={54 \over A\kern{-.8pt}C}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C={54 \over \sin(51\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈69{,}5\text{.}\) 1p 3p c Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=56\text{,}\) \(L\kern{-.8pt}M=62\) en \(\angle K=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\sin(\angle M)={K\kern{-.8pt}L \over L\kern{-.8pt}M}\) ofwel \(\sin(\angle M)={56 \over 62}\text{.}\) 1p ○ Hieruit volgt \(\angle M=\sin^{-1}({56 \over 62})\text{.}\) 1p ○ Dus \(\angle M≈64{,}6\degree\text{.}\) 1p 3p d Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=54\text{,}\) \(\angle K=46\degree\) en \(\angle L=90\degree\text{.}\) Cosinus (1) 007j - Sinus, cosinus en tangens - basis - 0ms d Cosinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\cos(\angle K)={K\kern{-.8pt}L \over K\kern{-.8pt}M}\) ofwel \(\cos(46\degree)={K\kern{-.8pt}L \over 54}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}L=54⋅\cos(46\degree)\text{.}\) 1p ○ Dus \(K\kern{-.8pt}L≈37{,}5\text{.}\) 1p opgave 23p a Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(L\kern{-.8pt}M=60\text{,}\) \(\angle L=42\degree\) en \(\angle M=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\cos(\angle L)={L\kern{-.8pt}M \over K\kern{-.8pt}L}\) ofwel \(\cos(42\degree)={60 \over K\kern{-.8pt}L}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}L={60 \over \cos(42\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}L≈80{,}7\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=52\text{,}\) \(K\kern{-.8pt}M=74\) 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 \(\cos(\angle K)={52 \over 74}\text{.}\) 1p ○ Hieruit volgt \(\angle K=\cos^{-1}({52 \over 74})\text{.}\) 1p ○ Dus \(\angle K≈45{,}4\degree\text{.}\) 1p |