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Math Help :(

Hey Guys:smile:

I need help with two math questions.:frown:

1.3sinx+1=4.8 , 0<x<2π

2. f(x)= x+1 0≤ x<2
4x-10 2≤x≤5
15-3x 5<x≤6
plot a graph of this function, stating its domain and range
evaluate f(0), f(4) and f(6)

Thank you so much for the help I would really appreciate it.
Reply 1
Avatar for TenOfThem
TenOfThem
18
Original post by YogieBear1001
Hey Guys:smile:

I need help with two math questions.:frown:

1.3sinx+1=4.8 , 0<x<2π

2. f(x)= x+1 0≤ x<2
4x-10 2≤x≤5
15-3x 5<x≤6
plot a graph of this function, stating its domain and range
evaluate f(0), f(4) and f(6)

Thank you so much for the help I would really appreciate it.



No problem

Let's start with Q1

What help do you need
Reply 2
Avatar for YogieBear1001
YogieBear1001
OP
5
Original post by TenOfThem
No problem

Let's start with Q1

What help do you need


Thank you so much:smile:

Q1 is 3sinx+1=4.8 , 0<x<2π
Reply 3
Avatar for TenOfThem
TenOfThem
18
Original post by YogieBear1001
Thank you so much:smile:

Q1 is 3sinx+1=4.8 , 0<x<2π


Yes, I saw

What help do you need

How far have you got
Reply 4
Avatar for YogieBear1001
YogieBear1001
OP
5
Original post by TenOfThem
Yes, I saw

What help do you need

How far have you got


3sinx+1=4.8 , 0<x<2π

I think im calculating it all wrong, but this bit --->+1=4.8 , 0<x<2π is confusing me.
Reply 5
Avatar for TenOfThem
TenOfThem
18
Original post by YogieBear1001
3sinx+1=4.8 , 0<x<2π

I think im calculating it all wrong, but this bit --->+1=4.8 , 0<x<2π is confusing me.


subtract 1

So you have 3Sinx=3.8
Reply 6
Avatar for joostan
joostan
13
Original post by YogieBear1001
3sinx+1=4.8 , 0<x<2π

I think im calculating it all wrong, but this bit --->+1=4.8 , 0<x<2π is confusing me.


I see TenOfThem's offline, so I'll try and help. :smile:
Is this the correct question? As I'm fairly sure the only solutions are complex. . .
Reply 7
Avatar for YogieBear1001
YogieBear1001
OP
5
Original post by joostan
I see TenOfThem's offline, so I'll try and help. :smile:
Is this the correct question? As I'm fairly sure the only solutions are complex. . .


Thank you:smile:
yes it is
Reply 8
Avatar for joostan
joostan
13
Original post by YogieBear1001
Thank you:smile:
yes it is


Do you know about sinh(x) and complex numbers?
(edited 10 years ago)
Reply 9
Avatar for m-s-96
m-s-96
8
The angles are in radians; 2pi = 360 deg

3sinx+1=4.8
3sinx=3.8
sinx=3.8/3
sin-1(3.8/3) =

The rest is to you.
Original post by m-s-96
The angles are in radians; 2pi = 360 deg

3sinx+1=4.8
3sinx=3.8
sinx=3.8/3
sin-1(3.8/3) =

The rest is to you.


Oh Yes! Thank you so much:smile:
Reply 11
Avatar for m-s-96
m-s-96
8
Original post by YogieBear1001
Oh Yes! Thank you so much:smile:


No problem.:smile:
Reply 12
Avatar for davros
davros
16
Original post by YogieBear1001
Hey Guys:smile:

I need help with two math questions.:frown:

1.3sinx+1=4.8 , 0<x<2π



You're going to have a problem with that!

As x varies between 0 and 2pi, sinx takes on values from -1 to +1 so the max value of 3sin x is 3 and the max value of 3sin x + 1 is 4 - you can never reach 4.8 with real values of x!
Original post by davros
You're going to have a problem with that!

As x varies between 0 and 2pi, sinx takes on values from -1 to +1 so the max value of 3sin x is 3 and the max value of 3sin x + 1 is 4 - you can never reach 4.8 with real values of x!


Thank you!:smile:
Reply 14
Avatar for m-s-96
m-s-96
8
Original post by davros
You're going to have a problem with that!

As x varies between 0 and 2pi, sinx takes on values from -1 to +1 so the max value of 3sin x is 3 and the max value of 3sin x + 1 is 4 - you can never reach 4.8 with real values of x!


The value for 'x' stated in the question represents the angle, not the value after applying sin.

Yes you are correct, sin only takes -1 to +1 and therefore 3sin + 1 is -4 to 4

:P

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