help on this question

[Inside Out]

How do you solve this question?  :DShow that the derivative of (x²+a²)^1/2   equals x/((x²+a²)^1/2)

[98.40_for_sure]

Let u = x^2 + a^2
du/dx = 2x

let y = u^(1/2)
dy/du = 1/2u^(-1/2)

dy/dx = 2x x 1/2u^(-1/2)
=2x/(2(x^2+a^2)^(1/2)
=x/((x^2+a^2)^(1/2))

[brightsky]

Just directly apply the chain rule.

as required.

[Inside Out]

Let u = x^2 + a^2
du/dx = 2x
how did u get that^
wouldn't du/dx= 2x + 2a

[Stroodle]

Nope. You're differentiating with respect to x.
a is a constant, imagine it's just another number like 1 or something.

[Inside Out]

ohhh i get it thanks

[m@tty]

Nope. You are only differentiating with respect to x. You treat as a constant, so it is not present in the derivative.

EDIT: Beaten...