help needed! URGENT!!! (1 Viewer)

[Kobe!!!]

Can someone please help me differentiating this?

3x + x = ?

doing my head in!
cheers!

 

[DownInFlames]

3x + x = 4x, which is differentiated to 4...

 

[kurt.physics]

Can someone please help me differentiating this?

3x + x = ?

doing my head in!
cheers!

Are you sure this is suposed to be in the 4 unit forum?

I will just elaborate what DownInFlames wrote.

3x + x = 4x

using the rule

dy/dx (xⁿ) = nx^n-1

dy/dx (4x¹) = 1 * 4 * x^1-1

= 1 * 4 * 1 (x⁰ = 1)

= 4

If, for some reason, you accedentally forgot to write x² instead of x, then to differentiate this it would be

dy/dx (x² + 3x) = 2x^2-1 + 3

= 2x + 3

 

[3unitz]

f(x) = 3x + x
f(x + h) = 3(x + h) + (x + h)

f'(x) = lim h->0 [f(x+h) - f(x)] / h
= lim h->0 [3(x + h) + (x + h) - 3x - x]/ h
= lim h->0 4h/ h
= lim h->0 4
= 4

 

[Forbidden.]

f(x) = 3x + x
f(x + h) = 3(x + h) + (x + h)

f'(x) = lim h->0 [f(x+h) - f(x)] / h
= lim h->0 [3(x + h) + (x + h) - 3x - x]/ h
= lim h->0 4h/ h
= lim h->0 4
= 4

Differentiation by first principles/definition of differential calculus.
Win.

 

[kaz1]

This thread is so lol for 4 unit.

 

[doink]

dy/dx (3x + x)
=dy/dx(3x) + dy/dx(x)
= 3 + 1
= 17

DUHH

don't know where all these idiots got 4 from, blatantly incorrect.

 

[kurt.physics]

dy/dx (3x + x)
=dy/dx(3x) + dy/dx(x)
= 3 + 1
= 17

DUHH

don't know where all these idiots got 4 from, blatantly incorrect.

...lol...