Saturday

March 28, 2015

March 28, 2015

Posted by **yuni** on Saturday, December 24, 2011 at 9:51pm.

a)the angle between a+b and a-b

b)lamdar if vector a is perpendicular to b+lamdar k.

- math -
**drwls**, Sunday, December 25, 2011 at 6:26amHow do you define "lambdar" ?

As for part (a), compute these two vectors:

a + b = 4i +j +0k

a - b = 2i -5j +4k

Their magnitudes are:

|a+b| = sqrt(16 + 1) = sqrt17

|a-b| = sqrt(4 +25 + 16) = sqrt45

(a+b)*(a-b) = 8 -5 = 3

= (sqrt17) x (sqrt45) cos theta

cos theta = 3/sqrt765 = 0.108

theta = 83.8 degrees

In the above, * denotes a dot product and x denotes normal scalar multiplication

**Answer this Question**

**Related Questions**

Please Help asap for math - Given the following: vector u= [-2,-1,2] and vector ...

Math: Vectors - Find any vector w that is perpendicular to both vector "u = 3j...

Math - The position vectors A and B with respect to the origin O,(-8,5) are (12...

math - The position vectors of points A and B with respect to the origin 0, are...

math - The position vectors of points A and B with respect to the origin 0, are...

Maths Vector Helpppp - The points A and B have position vectors, relative to the...

math - Point T is the midpoint of a straight line AB. Given the position vectors...

science (physics) Need to solve this today please - (a) Express the vectors A, B...

Calculus - SORRY, i wrote this question wrong before ... u, v, w are UNIT ...

maths - Given that vector c and vector d are non zero vectors such that vector c...