Mathematics (1 Viewer)

[chrissayyy]

Who's bored and wants to help me with some math questions?

 

[SpiralFlex]

Who's bored and wants to help me with some math questions?

Shoot.

 

[chrissayyy]

Its on domains and functions, and I don't get it at all, any advice or working would be appreciated on how to do it
Find the domains of the following functions

F (x) = √9 - 6x < square root the whole equation
G(x) = 3√5x + 4 < cubed square root the whole equation
H(x) = x-2 / x²-4
M (x) = 4√9-x² < root 4 the whole equation

Cheers, in advance

 

[hscishard]

Given that f(x) = e^x, find the value/ordinate when the gradient is 0.213 giving reasons (given space 13 characters)

 

[AAEldar]

Its on domains and functions, and I don't get it at all, any advice or working would be appreciated on how to do it
Find the domains of the following functions

F (x) = √9 - 6x < square root the whole equation
G(x) = 3√5x + 4 < cubed square root the whole equation
H(x) = x-2 / x²-4
M (x) = 4√9-x² < root 4 the whole equation

Cheers, in advance

1. Set F(x) so you get and solve for x.

 

[SpiralFlex]

Its on domains and functions, and I don't get it at all, any advice or working would be appreciated on how to do it
Find the domains of the following functions

F (x) = √9 - 6x < square root the whole equation
G(x) = 3√5x + 4 < cubed square root the whole equation
H(x) = x-2 / x²-4
M (x) = 4√9-x² < 4 square root with the whole eqaution ?

1. Now ask yourself can you square root a negative?! Yes you can in 4 Unit mathematics, but not right now.

So



2. For the second question you can cube root any number so the domain is all real x.

3. The third question remember the denominator cannot be 0 so we can say:





x is all real, ,

4.The last question, since the fourth root of a number must be positive like question 2,







[NOTE]: It is very important to understand this concept, if you are unclear with anything I suggest you sketch a graph neatly.

 

[hscishard]

Its on domains and functions, and I don't get it at all, any advice or working would be appreciated on how to do it
Find the domains of the following functions

F (x) = √9 - 6x < square root the whole equation
G(x) = 3√5x + 4 < cubed square root the whole equation
H(x) = x-2 / x²-4
M (x) = 4√9-x² < root 4 the whole equation

Cheers, in advance

The domain is all the x coodinates except the ones where you can't square root a negative number. For 1., 9-6x>=0, x<=3/2
The range is all the possible y coodinates. This case, it's y>=0. You can get this from sketching the graph

 

[chrissayyy]

Thanks, for all your fast replies guys
and thanks SpiralFlex, once again for helping me with my problem haha
I think I'm sorta getting it now cheers!

 

[SpiralFlex]

Thanks, for all your fast replies guys
and thanks SpiralFlex, once again for helping me with my problem haha
I think I'm sorta getting it now cheers!

Feel free to PM me if you need any assistance or if you would like some homework.

 

[chrissayyy]

Feel free to PM me if you need any assistance or if you would like some homework.

Will do, Thanks

 

[SpiralFlex]

Will do, Thanks

Mind blank, I have corrected the answer to the last question.

Try some random questions:

 

[SpiralFlex]

Given that f(x) = e^x, find the value/ordinate when the gradient is 0.213 giving reasons (given space 13 characters)

Trick question?

 

[ohexploitable]

Given that f(x) = e^x, find the value/ordinate when the gradient is 0.213 giving reasons (given space 13 characters)

ln0.213, 0.213

using the thing how y-value is equal to gradient etc.

 

[hscishard]

^ yes
The 13 characters i was thinking of is:
f'(x)=y "therefore"0.213

 

[Omnipotence]

Next time, post in the Mathematics section.

 

[tranx]

Given that f(x) = e^x, find the value/ordinate when the gradient is 0.213 giving reasons (given space 13 characters)

well gradient = m and m = gradient function. So find the derivative (e^x lol) and put 0.213 = e^x then its ln(0.213) = x AND PRESTO your done. TOTALLY 13 characters i do ext. 2 maths (i would know)

 

[hscishard]

well gradient = m and m = gradient function. So find the derivative (e^x lol) and put 0.213 = e^x then its ln(0.213) = x AND PRESTO your done. TOTALLY 13 characters i do ext. 2 maths (i would know)

I'd give it 0/1. You didnt find the y value/ ordinate, i.e. didn't answer the question

 

[AAEldar]

I'd give it 0/1. You didnt find the y value/ ordinate, i.e. didn't answer the question

He does Ext. 2 Maths though, he would know.

 

[slyhunter]

hscishard does too.

 

[AAEldar]

hscishard does too.

I was being sarcastic/ironic because of the fact that he thinks he should get it right just because he does 4U >.<