On Monday, April 27th we’ll have a short test on Vectors. (It won’t take the whole period, and it won’t involve planes.)
The following questions may be helpful when studying for this test.
Page 427 question 11
Page 634 questions 6 a, 7, 8 b, 9 a, 10 b d, 14
Page 642–643 3, 18, 19
hello sir, could i come to our office tomorrow and go through the question with you that we did in class because im finding it really difficult to reach the answer and ive been trying for a solid hour and a half!
your*
oh no wait, I GOT IT! FINALLY RELIEF!
Sir, I am stuck with question 11 on page 427.
Try expanding the expressions \(|a+b|\) and \(|a-b|\).
Sir, I am stuck with question 18 and 19 on page 643.
Remember that vectors are perpendicular if the dot product is zero, and two vectors are parallel if one is a scalar multiple of the other. One hint: the cross product isn’t required for either (and is introduced in a later section of the textbook).
i still dont understand how to work out question 11 on page 427
Recall that \(|\vec{x}|=\sqrt{\vec{x}\cdot\vec{x}}\). Use this to expand the two expressions mentioned above; setting the resulting expressions equal will yield an equation that can be solved for \(a\cdot b\).
im also having trouble figuring out how 14 on page 634 is equal to route 14 over 14 because i have 1/ route 14
\(\pm\frac{1}{\sqrt{14}}\) is correct.