4.4 Övningar
Sommarmatte 1
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Övning 4.4:1
För vilka vinklar v, där 0 \leq v\leq 2\pi, gäller att
\textrm{a) } | \sin{v}=\displaystyle \frac{1}{2} | \textrm{b) } | \cos{v}=\displaystyle \frac{1}{2} | \textrm{c) } | \sin{v}=1 |
\textrm{d) } | \tan{v}=1 | \textrm{e) } | \cos{v}=2 | \textrm{f) } | \sin{v}=-\displaystyle \frac{1}{2} |
\textrm{g) } | \tan{v}=-\displaystyle \frac{1}{\sqrt{3}} | ||||
Facit till alla delfrågorna
\textrm{a) } | \displaystyle v=\frac{\pi}{6}, \displaystyle v=\frac{5\pi}{6} | \textrm{b) } | \displaystyle v=\frac{\pi}{3}, \displaystyle v=\frac{5\pi}{3} | \textrm{c) } | \displaystyle v=\frac{\pi}{2} |
\textrm{d) } | \displaystyle v=\frac{\pi}{4},\displaystyle v=\frac{5\pi}{4} | \textrm{e) } | \textrm{lösning saknas} | \textrm{f) } | \displaystyle v=\frac{11\pi}{6}, \displaystyle v=\frac{7\pi}{6} |
\textrm{g) } | \displaystyle v=\frac{5\pi}{6}, \displaystyle v=\frac{11\pi}{6} | ||||
Övning 4.4:2
Lös ekvationen
\textrm{a) } | \sin{x}=\displaystyle \frac{\sqrt{3}}{2} | \textrm{b) } | \cos{x}=\displaystyle \frac{1}{2} | \textrm{c) } | \sin{x}=0 |
\textrm{d) } | \sin{5x}=\displaystyle \frac{1}{\sqrt{2}} | \textrm{e) } | \sin{5x}=\displaystyle \frac{1}{2} | \textrm{f) } | \cos{3x}=-\displaystyle\frac{1}{\sqrt{2}} |
Facit till alla delfrågorna
\textrm{a) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{3}+2n\pi\cr x=\displaystyle\frac{2\pi}{3}+2n\pi } \right. |
\textrm{b) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{3}+2n\pi\cr x=\displaystyle\frac{5\pi}{3}+2n\pi } \right. |
\textrm{c) } | x=n\pi |
\textrm{d) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{20}+\displaystyle\frac{2n\pi}{5}\cr x=\displaystyle\frac{3\pi}{20}+\displaystyle\frac{2n\pi}{5} } \right. |
\textrm{e) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{30}+\displaystyle\frac{2}{5}n\pi\cr x=\displaystyle\frac{\pi}{6}+\displaystyle\frac{2}{5}n\pi } \right. |
\textrm{f) } | \left\{ \matrix{x=\displaystyle\frac{\pi}{4}+\displaystyle\frac{2}{3}n\pi\cr x=\displaystyle\frac{5\pi}{12}+\displaystyle\frac{2}{3}n\pi } \right. |
Övning 4.4:3
Lös ekvationen
a) | \cos{x}=\cos{\left( \displaystyle \frac{\pi}{6} \right)} | b) | \sin{x}=\sin{\left( \displaystyle \frac{\pi}{5} \right)} | c) | \sin{(x+40^\circ)}=\sin{65^\circ} | d) | \sin{3x}=\sin{15^\circ} |
Facit till alla delfrågorna
\textrm{a) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{6}+2n\pi\cr x=\displaystyle\frac{11\pi}{6}+2n\pi }\right. |
\textrm{b) } |
\left\{ \matrix{ x=\displaystyle\frac{\pi}{5}+2n\pi\cr x=\displaystyle\frac{4\pi}{5}+2n\pi }\right. |
\textrm{c) } |
\left\{ \matrix{ x=25^\circ + n\cdot 360^\circ\cr x=75^\circ + n\cdot 360^\circ }\right. |
\textrm{d) } |
\left\{ \matrix{ x=5^\circ + n \cdot 120^\circ \cr x= 55^\circ + n \cdot 120^\circ }\right. |
||||
Övning 4.4:4
Bestäm de vinklar v i intervallet 0^\circ \leq v \leq 360^\circ som uppfyller \cos{\left(2v+10^\circ\right)}=\cos{110^\circ}.
v_1=50^\circ, v_2=120^\circ, v_3=230^\circ och v_4=300^\circ
Övning 4.4:5
Lös ekvationen
\textrm{a) } | \sin{3x}=\sin{x} | \textrm{b) } | \tan{x}=\tan{4x} | \textrm{c) } | \cos{5x}=\cos(x+\pi/5) |
Facit till alla delfrågorna
\textrm{a) } |
\left\{ \matrix{ x=n\pi\cr x=\displaystyle \frac{\pi}{4}+\displaystyle \frac{1}{2}n\pi }\right. |
\textrm{b) } | x=\displaystyle \frac{1}{3}n\pi | \textrm{c) } |
\left\{\matrix{ x=\displaystyle \frac{\pi}{20}+\displaystyle \frac{1}{2}n\pi\cr x=-\displaystyle \frac{\pi}{30}+\displaystyle \frac{1}{3}n\pi }\right. |
Övning 4.4:6
Lös ekvationen
\textrm{a) } | \sin x\cdot \cos 3x = 2\sin x | \textrm{b) } | \sqrt{2}\sin{x}\cos{x}=\cos{x} | \textrm{c) } | |
Facit till alla delfrågorna
\textrm{a) } |
x=n\pi |
\textrm{b) } |
\left\{ \matrix{x=\displaystyle \frac{\pi}{4}+2n\pi\cr x=\displaystyle \frac{\pi}{2}+n\pi\cr x=\displaystyle \frac{3\pi}{4}+2n\pi}\right. |
\textrm{c) } | |
Lösning till delfråga b
Bild:4 4 6b.gif
Övning 4.4:7
Lös ekvationen
\textrm{a) } | 2\sin^2{x}+\sin{x}=1 | \textrm{b) } | 2\sin^2{x}-3\cos{x}=0 | \textrm{c) } | \cos{3x}=\sin{4x} |
Facit till alla delfrågorna
\textrm{a) } |
\left\{ \matrix{ x=\displaystyle \frac{\pi}{6}+2n\pi\cr x=\displaystyle \frac{5\pi}{6}+2n\pi\cr x=\displaystyle \frac{3\pi}{2}+2n\pi }\right. |
\textrm{b) } | x=\pm \displaystyle \frac{\pi}{3} + 2n\pi | \textrm{c) } |
\left\{ \matrix{ x=\displaystyle \frac{\pi}{2}+2n\pi\cr x=\displaystyle \frac{\pi}{14}+\displaystyle \frac{2}{7}n\pi }\right. |
Lösning till delfråga a
Bild:4 4 7a.gif
Lösning till delfråga b
Bild:4 4 7b.gif
Lösning till delfråga c
Bild:4 4 7c.gif
Övning 4.4:8
Lös ekvationen
\textrm{a) } | \sin{2x}=\sqrt{2}\cos{x} | \textrm{b) } | \sin{x}=\sqrt{3}\cos{x} | \textrm{c) } | \displaystyle \frac{1}{\cos^2{x}}=1-\tan{x} |
Facit till alla delfrågorna
\textrm{a) } |
\left\{ \matrix{ x=\displaystyle \frac{\pi}{4}+2n\pi\cr x=\displaystyle \frac{\pi}{2}+n\pi\cr x=\displaystyle \frac{3\pi}{4}+2n\pi }\right. |
\textrm{b) } | x=\displaystyle \frac{\pi}{3}+n\pi | \textrm{c) } |
\left\{ \matrix{ x=n\pi\cr x=\displaystyle \frac{3\pi}{4}+n\pi }\right. |
Lösning till delfråga a
Bild:4 4 8a.gif
Lösning till delfråga c
Bild:4 4 8c.gif