# Math Help - Geometric Vectors

1. ## Geometric Vectors

Could you please correct my answers for the following questions?

14) ABCD is a square of side length 3 cm.

a) State whether each statement is true or false. Explain.

1. False because it's not parallel
2. False because it's not parallel
3. True because they are the opposites of one another

b) Calculate the magnitude of AC.

4.24 cm

16) Explain your answer to each question. (Each of the letters suppose to have an arrow on the top pointing to the right)

a) If u = v, is it always true that |u| = |v|?

It's true because they are equivalent vectors.

b) If |u| = |v|, is it always true that u = v?

It's true because they are equivalent vectors.

2. Originally Posted by Macleef
Could you please correct my answers for the following questions?

14) ABCD is a square of side length 3 cm.
1. False because it's not parallel
2. False because it's not parallel
3. True because they are the opposites of one another

b) Calculate the magnitude of AC.

4.24 cm

16) Explain your answer to each question. (Each of the letters suppose to have an arrow on the top pointing to the right)
a) If u = v, is it always true that |u| = |v|?
It's true because they are equivalent vectors.

b) If |u| = |v|, is it always true that u = v?
It's true because they are equivalent vectors.
1 is correct; but 2 & 3 are incorrect.
Remember that $\left| {\overrightarrow {AB} } \right|$ stands for the length of the vector.

So you need to rethink these answers.

In 16 a is true but b is false. WHY?

3. Originally Posted by Plato
1 is correct; but 2 & 3 are incorrect.
Remember that $\left| {\overrightarrow {AB} } \right|$ stands for the length of the vector.

So you need to rethink these answers.

In 16 a is true but b is false. WHY?
For 2. is it true because both have the same length, so they are opposite vectors?

For 3. is it false because they are not opposites or even parallel to each other?

For 16., I don't get how they are not both true. Aren't they all opposites?

4. Originally Posted by Macleef
For 2. is it true because both have the same length, so they are opposite vectors? CORRECT

For 3. is it false because they are not opposites or even parallel to each other?
Not Correct Length is a non-negative number.
How can we have $\left| {\overrightarrow {BA} } \right| = \color{red}- \left| {\overrightarrow {CB} } \right|$? Length is not negative.

For 16., I don't get how they are not both true. Aren't they all opposites?
No they are not opposites!
One says equal vectors have equal lengths.
The other says that if two vevtors have equal length then the vectors are equal. That is false.