Question

LOST
Identify the real and imaginary parts, respectively, of a complex number.

5 - (-2i)
Select one:
a. -5 and -2
b. 5 and 2
c. -2 and 5
d. 2 and -5

Answer 1

i am going to bet that this is really \[5+2i\] making the real part 5 and the imaginary part 2

Answer 2

think of it as distributing the negative sign.

Answer 3

and i don't believe you are lost, since the only trick here was that \[5-(-2i)=5+2i\]

Answer 4

I dont get how to solve that or know how you even began to set that up

Answer 5

If you're given a complex number, the real part is the part that does not have the operator i associated with it. The imaginary part does have the operator i associated with it. These are definitions that need to be learned and remembered.

Answer 6

If its 3+6i = 3+ (-6)??

Answer 7

not necessarily

Answer 8

Then i dont get how to do that

Answer 9

3+ (-6) is equal to 3-6

Answer 10

oh dear
there is nothing to set up \[5-(-2x)=5+2x\] right ?

Answer 11

i.e. \[-(-2)=2\]

Answer 12

Starting with 5 - (-2i): Please focus on the -(-2i). This simplifies to what? What is (-1)(-1)?

I agree with satellite that 5 - (-2i) can be re-written as 5 + 2i.
This complex number has two terms. Which term is real (has no i associated with it)?:
Which term is imaginary (has i associated with it)?:

Answer 13

If you can answer those two questions, you'll be done.

Answer 14

if there both positive it stays the same right?

Answer 15

remember these ground rules:,
**a positive number subtracted by a negative number will ALWAYS be positive
Example : 5-(-6)=11

**a negative number subtracted by a positive number will ALWAYS be negative
Example: -5-(6)=-11

**a positive number subtracted by a positive number...is just basic math really
Example: 5-6=-1 (since the 6 is greater than 5, the answer is negative)

**a negative number subtracted by a positive number...this one is tricky!
Example:-5-(-6)=1
remember, when there are two negative signs next to each other, the operation becomes like addition...so this could be rewritten as -5+6, which equals 1

Answer 16

^^hope this clears things up

Answer 17

what about a positive and positive theyll stay the same right?

Answer 18

you mean if a positive is subtracted by a positive?

Answer 19

no its added??? 3+6i

Answer 20

well then yes, it will always remain positive.

Answer 21

addition is pretty straight forward, but I could break that down for you too ^^ I only broke down subtraction up there for you lol

Answer 22

for this one its be D because both would be 0
-4 - (- 4i)
Select one:
a. -4 and 4
b. 4 and 0
c. 0 and 4
d. None of the above

Answer 23

Starting with 5 - (-2i): Please focus on the -(-2i). This simplifies to what? What is (-1)(-1)?

I agree with satellite that 5 - (-2i) can be re-written as 5 + 2i.
This complex number has two terms. Which term is real (has no i associated with it)?:
Which term is imaginary (has i associated with it)?:

Answer 24

More ground rules:

**A positive number added to a positive number is ALWAYS positive
Example: 5+6=11

**A positive number added to a negative number...depends
Example:5+(-6)=-1
this can be rewritten as 5-6, which equals -1

**A negative number added to a positive number...depends as well
Example: -5+6=1
Since 6 is large enough for -5 to become positive, 1 is the answer

**A negative number added to a negative number is ALWAYS negative
Example -5+(-6)=-11
this can be rewritten as -5-6, which is equal to -11

Answer 25

for this one its be D because it would equal 8 but thats not an answer??
-4 - (- 4i)
Select one:
a. -4 and 4
b. 4 and 0
c. 0 and 4
d. None of the above

Answer 26

Are you still trying to identify the imaginary/real parts of the number?

Answer 27

yes

Answer 28

In that case, I'm sorry to say that you may want to think again.

Think in this manner:

Answer 29

oh so its 4 and -4