Find the indicated quantities for y equals f (x )equals 3 x squared. ​(A) Simplify StartFraction f (3 plus Upper Delta x )minus f (3 )Over Upper Delta x EndFraction . ​(B) What does the quantity in part ​(A) approach as Upper Deltax approaches​ 0?

Respuesta :

Answer:

6x

Step-by-step explanation:

Given that a function f(x) is given as

[tex]y=f(x) = 3x^2[/tex]

A) [tex]f(x+ \Delta x) = 3((x+ \Delta x)^2=3(x^2+2x \Delta x+\Delta x^2)\\f(x) = 3x^2\\f(x+ \Delta x) -f(x) = 6x  \Delta x +\Delta x^2[/tex]

Now divide by delta x

[tex]\frac{f(x+ \Delta x) -f(x)}{\Delta x}\\=6x+\Delta x[/tex]

B) When delta x tends to 0, this becomes

[tex]6x[/tex]

(NOte: This is the derivative of f(x))