
#1
Oct711, 01:44 PM

P: 322

1. The problem statement, all variables and given/known data
if vector : line a starts from coordinates (0,0) and ends at (5,3) line b starts from coordinates (0,0) and ends at (1,2) What represents the vector: 2a5b 2. Relevant equations 3. The attempt at a solution I was initially thinking of computing Pythagorus theorem for each of the two lines. for Line a = square root of (25+9) = square root of 24 for line b = square root of (1+4) = square root of 5 2a5b = 2 x square root of 6  5 x square root of 5 which doesn't seem right...tips would be nice please. need an answer in the form of an x and y coordinate 



#2
Oct711, 02:05 PM

P: 1,195

Not sure of what 2a means. Does it mean a vector starting at (0,0) and ending at
(10,6)? Does 5b mean a vector starting at (0,0) and ending at (5,10)? 



#3
Oct711, 02:25 PM

P: 322

anyone else? tips or hints?




#4
Oct711, 02:28 PM

HW Helper
Thanks
P: 9,818

What represents the vector: 2a5b
2a means twice the vector a, a vector in the same line as a and of twice length. In coordinates, a=(5,3) and the vector is represented by an arrow starting at (0,0) and ending at (5,3). 2a=(10,6), 5b=(5,10)
2a5b means the difference between 2a and 5b. When you add (subtract) vectors, you add (subtract) the components. ehild 



#5
Oct711, 07:30 PM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 38,881

Most importantly, there is nothing here that asks you to find the length of any vector. Do not use the Pythagorean theorem!




#6
Oct811, 08:04 AM

P: 322

so if 2a=(10,6), 5b=(5,10)
and 2a5b then 105 = 5 610 = 4 therefore= 2a5b=(5,4) 



#7
Oct811, 08:05 AM

P: 322

thanks guys especially echild whats your qualifications?




#8
Oct911, 12:59 AM

HW Helper
Thanks
P: 9,818

You are welcome.
ehild 


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