Getal & Ruimte (13e editie) - havo wiskunde B
'Sinus, cosinus en tangens'.
| 3 havo | 6.3 Berekeningen met de tangens |
opgave 13p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R=40\text{,}\) \(\angle Q=44\degree\) en \(\angle R=90\degree\text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle Q)={P\kern{-.8pt}R \over Q\kern{-.8pt}R}\) ofwel \(\tan(44\degree)={P\kern{-.8pt}R \over 40}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}R=40⋅\tan(44\degree)\text{.}\) 1p ○ Dus \(P\kern{-.8pt}R≈38{,}6\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=29\text{,}\) \(\angle M=54\degree\) 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 \(\tan(54\degree)={29 \over K\kern{-.8pt}M}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}M={29 \over \tan(54\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}M≈21{,}1\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=26\text{,}\) \(P\kern{-.8pt}Q=42\) 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 \(\tan(\angle R)={42 \over 26}\text{.}\) 1p ○ Hieruit volgt \(\angle R=\tan^{-1}({42 \over 26})\text{.}\) 1p ○ Dus \(\angle R≈58{,}2\degree\text{.}\) 1p |
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| 3 havo | 6.4 De sinus en de cosinus |
opgave 13p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(B\kern{-.8pt}C=71\text{,}\) \(\angle C=37\degree\) en \(\angle A=90\degree\text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle C)={A\kern{-.8pt}B \over B\kern{-.8pt}C}\) ofwel \(\sin(37\degree)={A\kern{-.8pt}B \over 71}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B=71⋅\sin(37\degree)\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈42{,}7\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=55\text{,}\) \(\angle B=53\degree\) 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 \(\sin(53\degree)={55 \over A\kern{-.8pt}B}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B={55 \over \sin(53\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈68{,}9\text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=49\text{,}\) \(A\kern{-.8pt}B=70\) 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 \(\sin(\angle B)={49 \over 70}\text{.}\) 1p ○ Hieruit volgt \(\angle B=\sin^{-1}({49 \over 70})\text{.}\) 1p ○ Dus \(\angle B≈44{,}4\degree\text{.}\) 1p 3p d Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=71\text{,}\) \(\angle K=38\degree\) 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 \(\cos(38\degree)={K\kern{-.8pt}L \over 71}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}L=71⋅\cos(38\degree)\text{.}\) 1p ○ Dus \(K\kern{-.8pt}L≈55{,}9\text{.}\) 1p opgave 23p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=51\text{,}\) \(\angle A=37\degree\) en \(\angle B=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle A)={A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\cos(37\degree)={51 \over A\kern{-.8pt}C}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C={51 \over \cos(37\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈63{,}9\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(L\kern{-.8pt}M=56\text{,}\) \(K\kern{-.8pt}L=65\) en \(\angle M=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 0ms b Cosinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\cos(\angle L)={L\kern{-.8pt}M \over K\kern{-.8pt}L}\) ofwel \(\cos(\angle L)={56 \over 65}\text{.}\) 1p ○ Hieruit volgt \(\angle L=\cos^{-1}({56 \over 65})\text{.}\) 1p ○ Dus \(\angle L≈30{,}5\degree\text{.}\) 1p |