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# C1 Help :( watch

1. A curve has the equation y=3x-x^3/2

The curve meets the x axis at the origin and at the point A (where y is 0) and has a maximum at the point B

i) find the x coordinate of A

I know I need to make y 0 but I'm having such a hard time factorising it!
2. you can write

x ( 3 - x? ) = 0

to find ? you have to think about combining the powers of x and x? to make x3/2
3. (Original post by the bear)
you can write

x ( 3 - x? ) = 0

to find ? you have to think about combining the powers of x and x? to make x3/2
Thank you! I now have x(3-x^1/2) but I've never seen x^1/2 or the square root of x in a bracket before so I don't really know how to find x from it
4. If it is a root y=0
Therefore x (3-x^1/2)=0
Now if they equal zero either x=0 (the origin) or 3-x^1/2=0
Then x^1/2=3
Since x^1/2 is the same as square root
You know that the square root of x=3
From this you can find x

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5. (Original post by catrinellis)
A curve has the equation y=3x-x^3/2

The curve meets the x axis at the origin and at the point A (where y is 0) and has a maximum at the point B

i) find the x coordinate of A

I know I need to make y 0 but I'm having such a hard time factorising it!
For part ii u need to differntiate it
6. (Original post by Hanaan999)
If x^1/2-3=0
Then x^1/2=3
Since x^1/2 is the same as square root
You know that the square root of x=3
From this you can find x

Posted from TSR Mobile
Ahh thank you that makes sense
7. (Original post by catrinellis)
Thank you! I now have x(3-x^1/2) but I've never seen x^1/2 or the square root of x in a bracket before so I don't really know how to find x from it
so you have got x ( 3 - √x ) = 0

so either x = 0 which you were told

or 3 - √x = 0

so 3 = √x

how would you continue ?
8. (Original post by the bear)
so you have got x ( 3 - √x ) = 0

so either x = 0 which you were told

or 3 - √x = 0

so 3 = √x

how would you continue ?
x is 9!!!
9. (Original post by catrinellis)
x is 9!!!
http://s2.quickmeme.com/img/40/40b96...30963ed6c7.jpg

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