Question

Complex Numbers.
Does anyone know how to do those types of problems?

Answer 1

A student uses the quadratic formula to solve a quadratic equation and determines that one of the solutions is x = 4+ square root of -98
What are the values of a and b if this solution is written in the form x = a + bi, where a and b are real numbers?

Answer 2

HI!!

Answer 3

Hello!

Answer 4

there is a real real easy way to do this, also an easy way, and a hard way q

Answer 5

\[4+\sqrt{-98}\] can you write this in the form \(a+bi\) ?

Answer 6

hint, \(98=2\times 49\)

Answer 7

well i know sqrt of i = -1, correct?
so somehow i would determine that sqrt of 98 and sqrt of -1 is


ok no i cannnot lol

Answer 8

\[\sqrt{-98}=\sqrt{49\times 2\times (-1)}=\sqrt{49}\sqrt2\sqrt{-1}\]

Answer 9

so \(\sqrt{49}=?\)

Answer 10

Alrighty

7

Answer 11

good and what do you call \(\sqrt{-1}\)?

Answer 12

i?

Answer 13

right, what you said earlier

Answer 14

you can't do anything with \(\sqrt2\) so just leave it
\[4+\sqrt{-98}=4+7\sqrt{2}i\]

Answer 15

a = 4 and b = seven square root of two end square root
a = 4 and b = negative seven square root of two end square root
a = 4 and b = square root of 14 end square root
a = 4 and b = two square root of seven end square root

Answer 16

now be careful here \[4+7\sqrt{2}i=a+bi\] so \(a=4,b=7\sqrt2\)

Answer 17

guess it is the first one, sort of hard to read

Answer 18

yeah that one

Answer 19

I will post an actual photo of it lol. I have 4 other problems that i need help with.. some i am better at than this, would you mind helping?

Answer 20

@Misty1212 , Hats off ^_^

Answer 21

yeah first one

Answer 22

choose a

Answer 23

i have to run, i am sure you will get lots of help!

Answer 24

Alrighty thank you! :)

Answer 25

I think that I've done this one correctly considering the answer is x=+-3i

Answer 26

its a complex number

Answer 27

which means imaginary number

Answer 28

correct

Answer 29

Yay! :)

Answer 30

do u have any idea

Answer 31

Not really...

Answer 32

\[\frac{ 4 }{ 4 } \pm \frac{ \sqrt{-25} }{ 4 }\]

Answer 33

can u do it remaining part

Answer 34

C....

Answer 35

r u following

Answer 36

4/4 =1

4 goes into 4, 1 time
4 goes into 25, 5 times

5/1=5

Answer 37

Yes for the most part

Answer 38

Did i configure that correctly?

Answer 39

just find \[\sqrt{-25}\]value

Answer 40

oh lol 5

Answer 41

no
it is 5i

Answer 42

sorry i was going to correct myself, which isnt that the same as -5?

Answer 43

now
a+bi = \[1\pm 5i\]
compare it

Answer 44

sorry

Answer 45

You lost me

Answer 46

\[= 1\pm \frac{ 5 }{ 4 }i\]

Answer 47

a=1
b=5/4?

im not sure

Answer 48

There isnt an 'i' in the answer choices

Answer 49

exactly
u r correct

Answer 50

Making it answer choice A, correct?

Answer 51

yes

Answer 52

do u know why i is missing in the answer

Answer 53

Because it is + or -?

Answer 54

or because it cancels out

Answer 55

no
we r comparing a + bi with given problem
u can easily find a
but
b is coefficient of i [ mean the number before the i]
that's why we don't have i

Answer 56

Oh Lol duahh, lol thank you

Answer 57

lol nice