Getal & Ruimte (12e 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 \(B\kern{-.8pt}C=48\text{,}\) \(\angle B=56\degree\) en \(\angle C=90\degree\text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle B)={A\kern{-.8pt}C \over B\kern{-.8pt}C}\) ofwel \(\tan(56\degree)={A\kern{-.8pt}C \over 48}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C=48⋅\tan(56\degree)\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈71{,}2\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=20\text{,}\) \(\angle C=33\degree\) en \(\angle A=90\degree\text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle C)={A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\tan(33\degree)={20 \over A\kern{-.8pt}C}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C={20 \over \tan(33\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈30{,}8\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q=24\text{,}\) \(Q\kern{-.8pt}R=59\) 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 \(\tan(\angle P)={59 \over 24}\text{.}\) 1p ○ Hieruit volgt \(\angle P=\tan^{-1}({59 \over 24})\text{.}\) 1p ○ Dus \(\angle P≈67{,}9\degree\text{.}\) 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 \(P\kern{-.8pt}Q=62\text{,}\) \(\angle Q=59\degree\) en \(\angle R=90\degree\text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle Q)={P\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\sin(59\degree)={P\kern{-.8pt}R \over 62}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}R=62⋅\sin(59\degree)\text{.}\) 1p ○ Dus \(P\kern{-.8pt}R≈53{,}1\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=25\text{,}\) \(\angle B=40\degree\) 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 \(\sin(40\degree)={25 \over A\kern{-.8pt}B}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B={25 \over \sin(40\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈38{,}9\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=52\text{,}\) \(P\kern{-.8pt}Q=56\) en \(\angle R=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle Q)={P\kern{-.8pt}R \over P\kern{-.8pt}Q}\) ofwel \(\sin(\angle Q)={52 \over 56}\text{.}\) 1p ○ Hieruit volgt \(\angle Q=\sin^{-1}({52 \over 56})\text{.}\) 1p ○ Dus \(\angle Q≈68{,}2\degree\text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=60\text{,}\) \(\angle P=32\degree\) 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 \(\cos(32\degree)={P\kern{-.8pt}Q \over 60}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q=60⋅\cos(32\degree)\text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q≈50{,}9\text{.}\) 1p opgave 23p a Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=58\text{,}\) \(\angle K=40\degree\) en \(\angle L=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\cos(\angle K)={K\kern{-.8pt}L \over K\kern{-.8pt}M}\) ofwel \(\cos(40\degree)={58 \over K\kern{-.8pt}M}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}M={58 \over \cos(40\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}M≈75{,}7\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(B\kern{-.8pt}C=56\text{,}\) \(A\kern{-.8pt}B=70\) en \(\angle C=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 1ms b Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle B)={B\kern{-.8pt}C \over A\kern{-.8pt}B}\) ofwel \(\cos(\angle B)={56 \over 70}\text{.}\) 1p ○ Hieruit volgt \(\angle B=\cos^{-1}({56 \over 70})\text{.}\) 1p ○ Dus \(\angle B≈36{,}9\degree\text{.}\) 1p |