SOLUTION: A) Find the inner product of a and b if a = <4, 5/4, -1/3> and b = < 1/2, -2, -3/2>, and state whether the vector are perpendicular. a. 5; no b. 5; yes c. 0; yes d. 0; no B)

Algebra.Com
Question 346160: A) Find the inner product of a and b if a = <4, 5/4, -1/3> and b = < 1/2, -2, -3/2>, and state whether the vector are perpendicular.
a. 5; no
b. 5; yes
c. 0; yes
d. 0; no
B) Find the cross product of v and w if v = <-1/3, 4, -3/8> and w = < 6, -4/5, 4>

Answer by nyc_function(2741)   (Show Source): You can put this solution on YOUR website!
Please, post one question at a time. I will answer part (a).

Let's compute the inner product, since that will maybe help with deciding which answer to pick.
a•b = 4(1/2) + (5/4)(-2) + (-1/3)(-3/2)
= 2 - 5/2 + 3/2
= 0
Then that narrows it down to (c) or (d).
Two vectors are perpendicular when their dot product is the cosine of 90 degrees, which is, as you may recall, 0.
Then (c) the correct answer.
============================
I decided to help you with question (b) as well.

Here we have

v = -i/3, 4j, -3k/8

w = 6i, -4j/5, 4k

v x w = (-i/3, 4j, -3k/8) x (6i, -4j/5, 4k)

v x w = 0 +4k/5 +4j/3 -24k +0 +16i -18j -12i/40 +0

v x w = (16 -12/40).i +(4/3 -18).j +(4/5 -24).k

v x w = 15.7(i) -50(j)/3 -116(k)/5 >================< ANSWER

RELATED QUESTIONS

Let vector space M22 have the inner product defined as tr(UTV). Find d(A,B) where A= (answered by ikleyn)
find the inner product of vector a and b if... (answered by ikleyn)
Show that vectors a and b are perpendicular. Vector a Vector b (2) (4) (answered by jim_thompson5910)
For each of the following choices of A and b, determine if b is in the column space of A... (answered by venugopalramana)
Consider the ordered bases B={[−5 0; -1 5],[4 0; 1 −4]} and C={[−1 0; -4 1],[4 0; 1 (answered by ikleyn)
Here T defined by .Find a vector “x” whose image under T is b, and determines whether x (answered by jim_thompson5910)
Let vector space M22 have the inner product defined as tr(U^T V ). Find the angle... (answered by ikleyn)
Solve the problem: Find the inner product of the vectors <2,5> and <4, -2>. Then state (answered by Fombitz,Edwin McCravy)
'Lines in 3-Space' lesson: 1. State where possible vector, parametric, and symmetric... (answered by ikleyn)