Asst 17 query

course Mth 271

I thought I had submitted this before, but I must have forgot to.

????????v?????assignment #017

017. `query 17

Applied Calculus I

11-14-2008

......!!!!!!!!...................................

14:38:53

2.5.2 inner, outer fns for (x^2-3x+3)^3

......!!!!!!!!...................................

RESPONSE -->

The inner function is (x^2-3x+3)

The outer function is u^3

confidence assessment:

.................................................

......!!!!!!!!...................................

14:39:20

The first function you evaluate is x^2 - 3x + 3.

You then cube this result.

So the breakdown to get f(g(x)) form is

f(z) = z^3

g(x) = x^2 - 3x + 3. **

......!!!!!!!!...................................

RESPONSE -->

self critique assessment: 3

.................................................

......!!!!!!!!...................................

14:40:34

2.5.8 inner, outer fns for (x+1)^-.5

......!!!!!!!!...................................

RESPONSE -->

f(z) = z^-.5

g(x) = x + 1

confidence assessment: 3

.................................................

......!!!!!!!!...................................

14:40:49

The first function you evaluate is x+1.

You then take this result to the -5 power.

So the breakdown to get f(g(x)) form is

f(z) = z^-.5

g(x) = x+1. **

......!!!!!!!!...................................

RESPONSE -->

self critique assessment: 3

.................................................

......!!!!!!!!...................................

17:12:11

2.5.24 der of f(t) = (9t+2)^(2/3) by gen power rule

......!!!!!!!!...................................

RESPONSE -->

f(t) = (9t+2)^(2/3)

using the general power rule

f'(t) = 2/3 * (9t+2) d/dt(9t+2)

f'(t) = 2/3 * (9t+2)(9)

f'(t) = 6(9t+2) = 54t + 12

confidence assessment: 3

.................................................

......!!!!!!!!...................................

17:13:37

This function is of the form u^(2/3), where u = 9 t + 2.

The derivative of f(t) = u^p is f ' (t) = p * u^(p-1) * u ', by the general power rule.

Here p = 2/3, and u ' = (9t + 2)' = 9 so we have

f ' (t) = p u^(p-1) * u ' = 2/3 * u^(2/3 - 1) * 9 = 6 * u^(-1/3), or since u = 9 t + 2

f ' (t) = 6 ( 9 t + 2)^(-1/3). **

......!!!!!!!!...................................

RESPONSE -->

I forgot that u needed to be raised to the p-1 power.

self critique assessment: 2

.................................................

......!!!!!!!!...................................

17:20:29

2.5.32 der of f(x) = (25+x^2)^(-1/2) by gen power rule

......!!!!!!!!...................................

RESPONSE -->

f(x) = (25+x^2)^(-1/2)

f(u) = x^(-1/2)

u(x) = 25+x^2

f'(x) = (-1/2)(25+x^2)^(-3/2) * (25+x^2)'

f'(x) = (-1/2)(25+x^2)^(-3/2) * 2x

f'(x) = -x(25+x^2)^(-3/2)

f'(x) = -x / (25+x^2)^(3/2)

confidence assessment: 3

.................................................

......!!!!!!!!...................................

17:20:50

Using inner function u = 25+x^2 and outer function = (u)^(-1/2) we get

n u^(n-1) du/dx is -1/2 * u^(-3/2) * 2x = - x ( 25+x^2)^(-3/2). **

......!!!!!!!!...................................

RESPONSE -->

self critique assessment: 3

.................................................

"