Question

ONE QUESTION .... URGENT!!!

Answer 1

@amorfide

Answer 2

@jdoe0001

Answer 3

I need help fast guys! Any help is AWESOME! I WILL MEDAL!

Answer 4

let f(x)=y
\[y=\sqrt{8x+10}\]
make x the subject

Answer 5

ok

Answer 6

\[y^{2}=8x+10\]

subtract 10 on both sides, then divide by 8

\[\frac{ y^{2}-10 }{ 8 }=x\]

now replace x with f^-1(x)
and replace y with x

Answer 7

ok and what do i do with that?

Answer 8

could i some how use that to solve it

Answer 9

after replacing x and y, you would get your inverse function

Answer 10

then you want to work out the domain of your inverse function

Answer 11

alright I got D

Answer 12

i marked it on the picture

Answer 13

how did you get D

Answer 14

I literally just told you what the function was and it is not D

Answer 15

ohh i think i see do i have to plug in and inverse everything>

Answer 16

if im correct about inversely then its C

Answer 17

you only need to find the inverse function, and domain of the function nothing else

Answer 18

did you even read anything I have wrote here omg

Answer 19

yes but I thought you meant inversing

Answer 20

ok one sec

Answer 21

how do i figure out the sign?

Answer 22

okay that is your funciton

Answer 23

the range of the original function is the domain of the inverse function

Answer 24

the domain is all possible x values you can put into the function
the range is all possible values that can be given out of the function

so if you have

f(x)=x+8

the domain is all possible x values that can be put into this are all numbers that exist

the range is all possible out comes, since you can put any x number in you can get any number given out so the range is all possible numbers

Answer 25

so go back to your original function

Answer 26

you know you can not square root a negative number

Answer 27

ok would it be this < then from reading that ^

Answer 28

considering that i can get any number out of a of the range

Answer 29

hmm im guessing thats a no.. well rats

Answer 30

heheh

Answer 31

your result is correct for the inverse btw

Answer 32

so i was right?

Answer 33

now which one is it, \(\bf x\le 10\ or \ x \ge 10\)

Answer 34

i think its <

Answer 35

well look at the original radicand

the "x" in the original equation, is the "domain" for it

what "x" MUST NOT BE in order for the radical \(\bf \sqrt{8x+10}\)to remain positive?

Answer 36

-

Answer 37

> or < hmmm

Answer 38

lemme try a few combinations \(\large \begin{array}{ccllll}
term&value
\\\hline\\
1&\sqrt{8(1)+10}\to \sqrt{18}\\
2&\sqrt{8(2)+10}\to \sqrt{26}\\
-1&\sqrt{8(-1)+10}\to \sqrt{-2}\\
-2&\sqrt{8(-2)+10}\to \sqrt{-6}\\
\end{array}\)

Answer 39

is it > /

Answer 40

is it? recall, a negative value inside a square root, gives an "imaginary" number

Answer 41

well then whats that imaginary number?

Answer 42

ani imaginary number, means, there's no solution, or is non-existent, thus imaginary

Answer 43

so "x" MUST NOT BE some value that makes the radicand negative

Answer 44

ok thanks bro or girl but im gonna go with the > option

Answer 45

yw

Answer 46

radicand means number right?

Answer 47

radicand = number inside the radical or root

Answer 48

or expression for that matter

Answer 49

then its HAS to be >0

Answer 50

if that is the right number?

Answer 51

yeap, if x = 0 then 8x + 10 gives 10
if x is a negative number, then you end up with a negative inside
thus \(\large \bf x \ge 0\)