Yksikkövektori vektorin $$$\left\langle 3 \sin^{2}{\left(t \right)} \cos{\left(t \right)}, - 3 \sin{\left(t \right)} \cos^{2}{\left(t \right)}, \sin{\left(2 t \right)}\right\rangle$$$ suunnassa
Syötteesi
Etsi yksikkövektori $$$\mathbf{\vec{u}} = \left\langle 3 \sin^{2}{\left(t \right)} \cos{\left(t \right)}, - 3 \sin{\left(t \right)} \cos^{2}{\left(t \right)}, \sin{\left(2 t \right)}\right\rangle$$$:n suuntaan.
Ratkaisu
Vektorin pituus on $$$\mathbf{\left\lvert\vec{u}\right\rvert} = \frac{\sqrt{26 - 26 \cos{\left(4 t \right)}}}{4}$$$ (vaiheet: katso vektorin pituuslaskin).
Yksikkövektori saadaan jakamalla annetun vektorin jokainen komponentti sen pituudella.
Näin ollen yksikkövektori on $$$\mathbf{\vec{e}} = \left\langle \frac{6 \sqrt{26} \sin^{2}{\left(t \right)} \cos{\left(t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}, - \frac{6 \sqrt{26} \sin{\left(t \right)} \cos^{2}{\left(t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}, \frac{2 \sqrt{26} \sin{\left(2 t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}\right\rangle$$$ (vaiheista ks. vektorin skalaarikertolaskin).
Vastaus
Yksikkövektori $$$\left\langle 3 \sin^{2}{\left(t \right)} \cos{\left(t \right)}, - 3 \sin{\left(t \right)} \cos^{2}{\left(t \right)}, \sin{\left(2 t \right)}\right\rangle$$$A:n suunnassa on $$$\left\langle \frac{6 \sqrt{26} \sin^{2}{\left(t \right)} \cos{\left(t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}, - \frac{6 \sqrt{26} \sin{\left(t \right)} \cos^{2}{\left(t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}, \frac{2 \sqrt{26} \sin{\left(2 t \right)}}{13 \sqrt{1 - \cos{\left(4 t \right)}}}\right\rangle\approx \left\langle \frac{2.353393621658208 \sin^{2}{\left(t \right)} \cos{\left(t \right)}}{\left(1 - \cos{\left(4 t \right)}\right)^{0.5}}, - \frac{2.353393621658208 \sin{\left(t \right)} \cos^{2}{\left(t \right)}}{\left(1 - \cos{\left(4 t \right)}\right)^{0.5}}, \frac{0.784464540552736 \sin{\left(2 t \right)}}{\left(1 - \cos{\left(4 t \right)}\right)^{0.5}}\right\rangle.$$$A