[COmtbiker12]

Yea I know that I'm not in Calc or anything super complicated but these imaginary numbers are confusing me.

Can you guys help me solve these problems with explanations as to how you do them?

1. Write the following in standard form.
2+5i
5+2i

2. Find the absolute value of the following.
a. |3-4i|
b. |-2-i|
c. |-9+6i}



I know they are probably easy but they're confusing me at the moment since my teacher didn't explain them too well. Thanks,
Tony

 

[escapeartist]

do u have a ti-83 graphing calculator?

 

[COmtbiker12]

Yup, how do you put in imaginary numbers on it though?

 

[escapeartist]

Ok. First you have to hit "mode," which is right next to the 2nd key, then scroll down to the 7th option on the screen, chances are "Real" is selected, you want to select "a+bi" then hit secob quit to get back to the regular screen. When you want to insert an "i" for imaginary hit "second" then the decimal, which is in the middle of the bottom row of buttons, that should do it

 

[COmtbiker12]

Thank you so much! lol, that makes it a lot easier.

 

[escapeartist]

Ya, i was counting on that then as my teacher was passing out the tests last week she said we couldnt use our calculators, so I had all of 30 seconds to learn imaginary numbers

 

[COmtbiker12]

Ya, i was counting on that then as my teacher was passing out the tests last week she said we couldnt use our calculators, so I had all of 30 seconds to learn imaginary numbers

Lol, that sucks. On Ti-83s to get absolute values you hit math, scroll right to Num, then its "abs(" right?

 

[escapeartist]

ya, i think so

 

[mack]

haha, ****in i, my teacher was sick today, so we didnt got no crap like that today!

alegbra 2 is officially useless.

 

[The Kadvang]

On a related note, I have a bet with this senior in my math class that whoever has a better grade, the loser pays off the difference in points in dollars. I'm up by $23.00.

 

[COmtbiker12]

On a related note, I have a bet with this senior in my math class that whoever has a better grade, the loser pays off the difference in points in dollars. I'm up by $23.00.

HAHA, thast a good bet. All the people in my Algebra2 class are either sophmores(like me) or freshmen.

 

[ioscope]

Yea I know that I'm not in Calc or anything super complicated but these imaginary numbers are confusing me.

Can you guys help me solve these problems with explanations as to how you do them?

1. Write the following in standard form.
2+5i
5+2i

2. Find the absolute value of the following.
a. |3-4i|
b. |-2-i|
c. |-9+6i}



I know they are probably easy but they're confusing me at the moment since my teacher didn't explain them too well. Thanks,
Tony

To divide
multiply by 1 in the form of the comlex conjugate (a-bi)/(a-bi)
in this case multiply by (5-2i)/(5-2i) distribute the numerator
the denominator should be 25+4 or 29
the numerator is FOIL distribute (2+5i)(5-2i)= 10-4i+25i-10i^2=20+21i

so it's 20+21i
29

I think

 

[The Kadvang]

HAHA, thast a good bet. All the people in my Algebra2 class are either sophmores(like me) or freshmen.

Yeah its awesome. I'm banking on second semester when senioritis kicks in.