What is $|| <4, 5, -7 > - < 9, -2, 1 > ||$ ?

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Answer 1 · 2016-12-28T01:50:13

$|< 4,5,-7 > - < 9,-2,1 >|=sqrt(138)$

Given $veca=< 4,5,-7 >$ and $vecb=< 9,-2,1 >$ , we can subtract $vecb$ from $veca$ by subtracting the components of $vecb$ from those of $veca$ .

$< 4,5,-7 > - < 9,-2,1 >$

$=> < (4-9), (5-(-2)), (-7-1) >$

$=>< -5, 7, -8 >$

Let's call this new vector $vecc$ , where $vecc=< c_x,c_y,c_z >$ . The magnitude of $vecc$ is then given by:

$|vecc|=sqrt((c_x)^2+(c_y)^2+(c_z)^2)$

$=>|vecc|=sqrt((-5)^2+(7)^2+(-8)^2)$

$=>|vecc|=sqrt(25+49+64)$

$=>|vecc|=sqrt(138)$

$:.|< 4,5,-7 > - < 9,-2,1 >|=sqrt(138)$

What is || <4, 5, -7 > - < 9, -2, 1 > |||| <4, 5, -7 > - < 9, -2, 1 > ||?