TRENDING NEWS

POPULAR NEWS

Find The Difference Quotient

Find the Difference Quotient for f(x)=2x^2-3x+2?

With f(x) = 2x^2 - 3x + 2, we have:
f(x + h) = 2(x + h)^2 - 3(x + h) + 2.

Then, the difference quotient is:
[f(x + h) - f(x)]/h
= [2(x + h)^2 - 3(x + h) + 2 - (2x^2 - 3x + 2)]/h
= (2x^2 + 4xh + 2h^2 - 3x - 3h + 2 - 2x^2 + 3x - 2)/h
= (4xh + 2h^2 - 3h)/h, by simplifying
= [h(4x + 2h - 3)]/h, by factoring out h
= 4x + 2h - 3, by canceling h.

I hope this helps!

How do I find the Difference Quotient of 1/sqrt(x)?

f(x) = 1/√x

Difference quotient
= (f(x+h) − f(x)) / h
= (1/√(x+h) − 1/√x) / h
= √x √(x+h) (1/√(x+h) − 1/√x) / (h √x √(x+h))
= (√x − √(x+h)) / (h √x √(x+h))

To get rid of h in denominator, we can multiply numerator and denominator by (√x + √(x+h))

= (√x − √(x+h)) (√x + √(x+h)) / (h √x √(x+h) (√x + √(x+h)))
= (x − (x+h)) / (h √x √(x+h) (√x + √(x+h)))
= (−h) / (h √x √(x+h) (√x + √(x+h)))
= −1 / (√x √(x+h) (√x + √(x+h)))

Now the reason we put difference quotient in this form is because we can now find slope as h approaches 0 (i.e. slope at point (x, 1/√x)), which is
−1 / (√x √x (√x + √x)) = −1 / (x (2√x)) = −1/(2x√x) = −1/(2x^(3/2))

Find the difference quotient. f(x) = 7x^2 - 3x + 2?

f (x + h) = 7 * (x + h)² - 3 * (x + h) + 2

<=>

f (x + h) = 7x² + 14xh + h² - 3x - 3h + 2

<=>

f (x + h) - f (x) = 7x² + 14xh + h² - 3x - 3h + 2 - 7x² + 3x - 2 =

14xh - 3h + h²

<=>

(f (x + h) - f (x)) / h = 14x - 3 + h

=>

lim (f (x + h) - f (x)) / h = 14x - 3
h -> 0


Conclusion :

The derivation of f (x) is 14x - 3

Is there a way to find the difference quotient using a TI-83 Plus calculator?

The only function I know of on the TI-83 is to calculate the value of the derivative of a function. Example: what is the value of the derivative of f(x) = 3x^3 - 42x at x = 3.
Press the Math key
Arrow down to 8:nDeriv
enter
input:(3x^3-42x,x,3) enter
answer = 39.

For your limit definition method above...
lim h-->0 [3(x+h)^3-42(x+h) - 3x^3+42x]/h
= lim h-->0 [3x^3+9x^2h+9xh^2+3h^3-42x-42h-3x^2+42x]...
= lim h-->0 [9x^2h+9xh^2+3h^3-42h]/h
= lim h-->0 [9x^2 + 9xh + 3h^2 - 42]
taking the limit h-->0 = 9x^2 - 42

(a) Find the value of the difference quotient for s(x) = xx at x = 3 for each value of h below. Give your answers to 4 decimal places.?

f(x) = x^x
h= 0.1; (f(3.1)- f(3))/h = ((3.1)^(3.1) - (3)^3 ) / 0.1 = 63.5963
h=0.01 ; (f(3.01)-f(3))/0.01 = ((3.01)^(3.01) - (3)^3 ) / 0.01 = 57.307180
h=0.001 ; (f(3.001)-f(3))/0.001 = ((3.001)^(3.001) - (3)^3 ) / 0.001 = 56.7285387
h=0.0001 ; (f(3.0001)-f(3))/0.0001 = ((3.0001)^(3.0001) - (3)^3 ) / 0.0001 = 56.6689279
h=0.00001 ; (f(3.00001)-f(3))/0.00001 = ((3.00001)^(3.00001) - (3)^3 ) / 0.00001 = 56.6631714

s'(3) = 56.66

Given 5x^2 - 4x find the difference quotient?

[f(x+h)-f(x)]/h
f(x+h)-f(x)=5(x+h)^2-4(x+h)-f(x)=
5x^2+10xh+5h^2-4x-4h-5x^2+4x=
10xh+5h^2-4h.

(10xh+5h^2-4h)/h = 10x+5h-4

The difference quotient is:
10x+5h-4

Find the difference quotient for the function.?

So you have the formula : [f(x + h) - f(x)] / h.

1. f(x) = -4x - 1

To convert f(x) into f(x + h), you just replace x with x + h.
so wherever you see x in the equation, replace it with x + h.

Thus, f(x + h) = -4(x + h) - 1

Now we can substitute these into the difference quotient.

[f(x + h) - f(x)] / h = {[-4(x + h) - 1] - [-4x - 1]} / h

= (-4x - 4h - 1 + 4x + 1) / h

= -4h / h

= -4

2. f(x) = (-1/3)(x - 5), so, f(x + h) = (-1/3)(x + h - 5)

DQ = [(-1/3)(x + h - 5) - (-1/3)(x - 5)] / h

= (-x/3 - h/3 + 5/3 + x/3 - 5/3) / h

= (-h/3) / h

= -1/3

3. f(x) = x^2/4, so, f(x + h) = (x + h)^2/4

DQ = [(x + h)^2/4 - x^2/4] / h

= (x^2/4 + xh/2 + h^2/4 - x^2/4) / h

= (xh/2 + h^2/4) / h

= x/2 + h/4

How do you find the difference quotient for this given function. f(x)= 4+3x-x^2, f(3+h) - f(3)/h?

just plug in (3+h) for x, then 3 for x

4 + 3(3+h) - (3+h)^2 - (4 + 3(3) - 3^2) all over h

then do it out: 4 + 9 + 3h - (9 + 6h + h^2) - (4+9-9) over h

then simplify: 13 + 3h - 9 - 6h - h^2 - 4 over h
= -3h - h^2 over h

then factor out an h: h(-3 - h) over h and cancel the h
leaving -3 - h

which, as h → 0 is -3

TRENDING NEWS