Getal & Ruimte (13e editie) - 3 vwo
'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 \(B\kern{-.8pt}C=39\text{,}\) \(\angle B=48\degree\) 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 \(\tan(48\degree)={A\kern{-.8pt}C \over 39}\text{.}\) 1p ○ Hieruit volgt \(A\kern{-.8pt}C=39⋅\tan(48\degree)\text{.}\) 1p ○ Dus \(A\kern{-.8pt}C≈43{,}3\text{.}\) 1p 3p b Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=58\text{,}\) \(\angle Q=49\degree\) en \(\angle R=90\degree\text{.}\) Tangens (2) 007n - Sinus, cosinus en tangens - basis - 0ms b Tangens in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\tan(\angle Q)={P\kern{-.8pt}R \over Q\kern{-.8pt}R}\) ofwel \(\tan(49\degree)={58 \over Q\kern{-.8pt}R}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R={58 \over \tan(49\degree)}\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈50{,}4\text{.}\) 1p 3p c Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=38\text{,}\) \(A\kern{-.8pt}B=51\) en \(\angle A=90\degree\text{.}\) Tangens (3) 007o - Sinus, cosinus en tangens - basis - 0ms c Tangens in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\tan(\angle C)={A\kern{-.8pt}B \over A\kern{-.8pt}C}\) ofwel \(\tan(\angle C)={51 \over 38}\text{.}\) 1p ○ Hieruit volgt \(\angle C=\tan^{-1}({51 \over 38})\text{.}\) 1p ○ Dus \(\angle C≈53{,}3\degree\text{.}\) 1p |
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| 3 vwo | 6.4 De sinus en de cosinus |
opgave 13p a Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}R=49\text{,}\) \(\angle P=34\degree\) en \(\angle Q=90\degree\text{.}\) Sinus (1) 007g - Sinus, cosinus en tangens - basis - 0ms a Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle P)={Q\kern{-.8pt}R \over P\kern{-.8pt}R}\) ofwel \(\sin(34\degree)={Q\kern{-.8pt}R \over 49}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R=49⋅\sin(34\degree)\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈27{,}4\text{.}\) 1p 3p b Gegeven is \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) met \(K\kern{-.8pt}M=37\text{,}\) \(\angle L=41\degree\) en \(\angle M=90\degree\text{.}\) Sinus (2) 007h - Sinus, cosinus en tangens - basis - 0ms b Sinus in \(\triangle K\kern{-.8pt}L\kern{-.8pt}M\) geeft \(\sin(\angle L)={K\kern{-.8pt}M \over K\kern{-.8pt}L}\) ofwel \(\sin(41\degree)={37 \over K\kern{-.8pt}L}\text{.}\) 1p ○ Hieruit volgt \(K\kern{-.8pt}L={37 \over \sin(41\degree)}\text{.}\) 1p ○ Dus \(K\kern{-.8pt}L≈56{,}4\text{.}\) 1p 3p c Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q=40\text{,}\) \(Q\kern{-.8pt}R=62\) en \(\angle P=90\degree\text{.}\) Sinus (3) 007i - Sinus, cosinus en tangens - basis - 0ms c Sinus in \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) geeft \(\sin(\angle R)={P\kern{-.8pt}Q \over Q\kern{-.8pt}R}\) ofwel \(\sin(\angle R)={40 \over 62}\text{.}\) 1p ○ Hieruit volgt \(\angle R=\sin^{-1}({40 \over 62})\text{.}\) 1p ○ Dus \(\angle R≈40{,}2\degree\text{.}\) 1p 3p d Gegeven is \(\triangle P\kern{-.8pt}Q\kern{-.8pt}R\) met \(P\kern{-.8pt}Q=57\text{,}\) \(\angle Q=55\degree\) 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 \(\cos(55\degree)={Q\kern{-.8pt}R \over 57}\text{.}\) 1p ○ Hieruit volgt \(Q\kern{-.8pt}R=57⋅\cos(55\degree)\text{.}\) 1p ○ Dus \(Q\kern{-.8pt}R≈32{,}7\text{.}\) 1p opgave 23p a Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=47\text{,}\) \(\angle C=41\degree\) en \(\angle A=90\degree\text{.}\) Cosinus (2) 007k - Sinus, cosinus en tangens - basis - 0ms a Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle C)={A\kern{-.8pt}C \over B\kern{-.8pt}C}\) ofwel \(\cos(41\degree)={47 \over B\kern{-.8pt}C}\text{.}\) 1p ○ Hieruit volgt \(B\kern{-.8pt}C={47 \over \cos(41\degree)}\text{.}\) 1p ○ Dus \(B\kern{-.8pt}C≈62{,}3\text{.}\) 1p 3p b Gegeven is \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) met \(A\kern{-.8pt}C=42\text{,}\) \(B\kern{-.8pt}C=66\) en \(\angle A=90\degree\text{.}\) Cosinus (3) 007l - Sinus, cosinus en tangens - basis - 0ms b Cosinus in \(\triangle A\kern{-.8pt}B\kern{-.8pt}C\) geeft \(\cos(\angle C)={A\kern{-.8pt}C \over B\kern{-.8pt}C}\) ofwel \(\cos(\angle C)={42 \over 66}\text{.}\) 1p ○ Hieruit volgt \(\angle C=\cos^{-1}({42 \over 66})\text{.}\) 1p ○ Dus \(\angle C≈50{,}5\degree\text{.}\) 1p |