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 \(P\kern{-.8pt}R=39\text{,}\) \(\angle R=51\degree\) en \(\angle P=90\degree\text{.}\) Tangens (1) 007m - Sinus, cosinus en tangens - basis - 0ms a Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle R)={P\kern{-.8pt}Q \over P\kern{-.8pt}R}\) ofwel \(\tan(51\degree)={P\kern{-.8pt}Q \over 39}\text{.}\) 1p ○ Hieruit volgt \(P\kern{-.8pt}Q=39⋅\tan(51\degree)\text{.}\) 1p ○ Dus \(P\kern{-.8pt}Q≈48{,}2\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}L=46\text{,}\) \(\angle M=32\degree\) 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 \(\tan(32\degree)={46 \over K\kern{-.8pt}M}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}M={46 \over \tan(32\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}M≈73{,}6\text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=46\text{,}\) \(B\kern{-.8pt}C=27\) en \(\angle B=90\degree\text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle A)={B\kern{-.8pt}C \over A\kern{-.8pt}B}\) ofwel \(\tan(\angle A)={27 \over 46}\text{.}\) 1p ○ Hieruit volgt \(\angle A=\tan^{-1}({27 \over 46})\text{.}\) 1p ○ Dus \(\angle A≈30{,}4\degree\text{.}\) 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 \(A\kern{-.8pt}C=68\text{,}\) \(\angle A=42\degree\) 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 \(\sin(42\degree)={B\kern{-.8pt}C \over 68}\text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C=68⋅\sin(42\degree)\text{.}\) 1p ○ Dus \(B\kern{-.8pt}C≈45{,}5\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=54\text{,}\) \(\angle B=36\degree\) 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 \(\sin(36\degree)={54 \over A\kern{-.8pt}B}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}B={54 \over \sin(36\degree)}\text{.}\) 1p ○ Dus \(A\kern{-.8pt}B≈91{,}9\text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}B=55\text{,}\) \(B\kern{-.8pt}C=77\) en \(\angle A=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\sin(\angle C)={A\kern{-.8pt}B \over B\kern{-.8pt}C}\) ofwel \(\sin(\angle C)={55 \over 77}\text{.}\) 1p ○ Hieruit volgt \(\angle C=\sin^{-1}({55 \over 77})\text{.}\) 1p ○ Dus \(\angle C≈45{,}6\degree\text{.}\) 1p 3p d Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(B\kern{-.8pt}C=77\text{,}\) \(\angle C=40\degree\) en \(\angle A=90\degree\text{.}\) Cosinus (1) 007j - Sinus, cosinus en tangens - basis - 0ms d Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle C)={A\kern{-.8pt}C \over B\kern{-.8pt}C}\) ofwel \(\cos(40\degree)={A\kern{-.8pt}C \over 77}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C=77⋅\cos(40\degree)\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈59{,}0\text{.}\) 1p opgave 23p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=23\text{,}\) \(\angle R=39\degree\) 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 \(\cos(39\degree)={23 \over Q\kern{-.8pt}R}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R={23 \over \cos(39\degree)}\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈29{,}6\text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(Q\kern{-.8pt}R=28\text{,}\) \(P\kern{-.8pt}Q=40\) en \(\angle R=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 1ms 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 \(\cos(\angle Q)={28 \over 40}\text{.}\) 1p ○ Hieruit volgt \(\angle Q=\cos^{-1}({28 \over 40})\text{.}\) 1p ○ Dus \(\angle Q≈45{,}6\degree\text{.}\) 1p |