derivative (1 Viewer)

[fashionista]

cud sum 1 please derive the following so i can plz check i did them rite?
y=x^2 + sq.rt(4-x)
nup..thats the only one
thanx evereebodee

 

[korry]

uh don't u just do it as normal...so um....2x + 1/2(4-x)^3/2

 

[Xayma]

Originally posted by korry
uh don't u just do it as normal...so um....2x + 1/2(4-x)^3/2

Youre nearly right, you have to minus not add from the second power so you get

dy/dx=2x+1/2(4-x)^-1/2
dy/dx=2x+1/(2sqrt(4-x))

 

[martin310015]

shouldn't it be:
dy/dx=2x+1/2(4-x)^-1/2(-1) times it by negative one

so it becomes

dy/dx=2x-1/(2sqrt(4-x))

 

[Xayma]

Originally posted by martin310015
shouldn't it be:
dy/dx=2x+1/2(4-x)^-1/2(-1) times it by negative one

so it becomes

dy/dx=2x-1/(2sqrt(4-x))

No. You just go through the normal chain rule. Times the front by the product THEN minus one from the index.

 

[fashionista]

thanx heaps!!!!!!

 

[martin310015]

yeah but don't u have to derivative things inside the bracket.

Chain rule
times it by the index ,minus one from the index and multiply the derivative of the things in the bracket.

correct me if im wrong.........THANX

 

[Xayma]

Originally posted by martin310015
yeah but don't u have to derivative things inside the bracket.

Chain rule
times it by the index ,minus one from the index and multiply the derivative of the things in the bracket.

correct me if im wrong.........THANX

Oh yeah your right. Opps, goes and edits all his posts, thats what I get for doing it off my head.

 

[martin310015]

its ok.