Find the component form of v given its magnitude and the angle it makes with the positive x-axis.
||v||=3
v in direction 3i +4j

Question

Find the component form of v given its magnitude and the angle it makes with the positive x-axis. 
||v||=3
v in direction 3i +4j

anonymous · Answer

3i +4j has unit vector of 


3/5 i + 4/5 j

anonymous · Answer

we are going 3 unit in that direction

3(3/5 i + 4/5 j)=9/5 i + 12/5 j

anonymous · Answer

finding unit vector

vector/ magnitude


3 i + 4 j 

3^2+ 4^2=5^2

anonymous · Answer

why is it over 5???

anonymous · Answer

we need unit vector .  

unit vector =  vector/magnitude

magnitude=5

anonymous · Answer

i don't get how you got 5

anonymous · Answer

magnitude is attained by 

$$a i + b j$$

squaring each component , adding them together , and taking square root

$$\sqrt{a^2+b^2}$$

anonymous · Answer

ok... so i would do|dw:1325717460298:dw|

anonymous · Answer

|dw:1325717503338:dw|