Question

HELP I AM BEGGING YOU I WILL GIVE YOU A MEDAL/FAN!!! Which logarithmic graph can be used to approximate the value of y in the equation 4y = 8?

I honestly don't know where to even start.

Answer 1

@phi

Answer 2

anyone?

Answer 3

Well I can help you out.

Answer 4

Lets see, your equation is this :

\[\large{4y = 8}\]

Right ?

Answer 5

sorry I typed it wrong, it's \[4^{y}= 8\]

Answer 6

Okay

Answer 7

\[\large{4^y = 8}\]

Lets take log both sides

Answer 8

that would be log( base 4) 4^y = log(base 4) 8

Answer 9

we will get:

\[\large{\log(4^y) = \log 8}\]

\[\large{\implies y \log 4 = \log 8}\]

Yes

Answer 10

That's the part where I get stuck. I'm not really sure what to do after.

Answer 11

Now, \[\large{\log_4(4) = 1}\]

Answer 12

I have a doubt in my mind: The graphs are for what base? log base 4 or any other base ?

Answer 13

I think it Is log base 4

Answer 14

Was it given in the question ?

Answer 15

Because log 0 for whatever base is not defined but both graphs have show some value for it.

Answer 16

@ikram002p Can you check the graphs please ?

Answer 17

in the lesson, it said to take the log of whatever is the base; it said to take the log of 4

Answer 18

Well I am not sure that the graphs are correct :(

Can you wait till someone checks it ? @ganeshie8

Answer 19

don't you have any x on the expression?

Answer 20

here is the work I did to get the second choice, but im not sure if it is right;
4^y = x
log (base 4) 4^y = log (base 4) x
y = log (base 4) x

From there I graphed the logarithm

Answer 21

the graph of y =\(log_4 8\) is a horizontal line; it's not any of them

Answer 22

the value 8 is plugged in for x, so I think it would actually be \[y=\log _{4} x\]

Answer 23

so, the second one is the right answer

Answer 24

Reason, when x =8 , y = 1.5

Answer 25

thank you :) that's what I thought but I wasn't quite sure