find-the-direction-cosines-and-its-angles-on-2i-3j-

Question Number 10392 by ketto last updated on 06/Feb/17

f i n d t h e d i r e c t i o n c o s i n e s

a n d i t s a n g l e s o n

2 i - 3 j

Answered by mrW1 last updated on 07/Feb/17

\cos α = \frac{2}{\sqrt{2^{2} + {(- 3)}^{2}}} = \frac{2}{\sqrt{13}}

\cos β = \frac{- 3}{\sqrt{2^{2} + {(- 3)}^{2}}} = - \frac{3}{\sqrt{13}}

α = 56.3 °

β = 146.3 °

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