Help on chain rule

[Guest]

I've got major problem with three of the rule, specially when the question involving square roots

here's the question :
Y=1/sqrt(5x+12)

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this is what i did
u = 1/5x+12
y = u^0.5

du\dx = 1/5

dy/dx = 0.5u^0.5*1/5
0.5(1/5x+1.2)^-0.5 *1/5

Thanks in advance ^^

 

[Frogger888]

Here is what I am getting just applying the chain rule
I first take inverse and get

(5x+12)^(-1/2) next

-(1/2)*5*[(5x+12)^((-1/2)-1)

remember
d/dx([f(x)^n)=n[f(x)^(n-1)*derivitive of f(x)

 

[Guest]

thank you ^^ that help a lot

Here is what I am getting just applying the chain rule
I first take inverse and get

(5x+12)^(-1/2) next

-(1/2)*5*[(5x+12)^((-1/2)-1)

remember
d/dx([f(x)^n)=n[f(x)^(n-1)*derivitive of f(x)