I need fast HELP

**jaycas21** · August 6th 2006, 08:41 AM

amount of natural gas is proportional to oxygen consumed. 24.0 kg of Oxygen is
consumed in burning 15 kg of gas how much air 23% oxygen by wieght is consumed to burn 50 kg

a.80 kg
b 345 kg
c. 31.3 kg
d. 135 kg

4.Which of the following expressions would help estimate the value of:
Which of the following expressions would help estimate the value of:
[IMG]

a.36
b.29.25
c.t
d.43

5.During each microsecond the current in an electric circuit decreases by 9.3%. If the initial current is 2.45 mA, what will the current be after 22 microseconds?

0.286 mA
0.496 mA
0.121 mA
1.24 mA

7.The sales S of a product as a function of the time t (in weeks) is given by S = [2300 (5t + 1)]/(2t + 5). Find the instantaneous rate of change of S with respect to t for t = 9 weeks.

125
51
900
100

**ThePerfectHacker** · August 6th 2006, 08:56 AM

2. y= 5x^2 sqrt (x+1) find dx/dy

Product rule,
$y'=(5x^2)'\sqrt{x+1}+(5x^2)(\sqrt{x+1})'$
Thus,
$y'=10x\sqrt{x+1}+\frac{5x^2}{2\sqrt{x+1}}$
Thus,
$y'=5x\sqrt{x+1}\left(2+\frac{x}{2(x+1)} \right)$

6.
Find the slope of the tangent to the curve of y = ln (25x + 3) at x = 2.

a.0.47
b.0.50
c.1.2
d.2.5

$y'=\frac{25}{25x+3}$ ---> By chain rule,
At $x=2$
$y'=\frac{25}{25(2)+3}$
Thus,
$y'\approx .47$

8.Find the center and radius of the circle: x2 + y2 - 18y = -17

Center = (9,0), r = - 8
Center = (1,8), r = 9
Center = (8,1), r =9
Center = (0,9), r = 8

You need to "complete-the-square".
$x^2+(y^2-18y+81)-81=-17$
Thus,
$(x-0)^2+(y-9)^2=64=8^2$
Thus,
$\mbox{center }=(0,9)$
$\mbox{radius }=8$

**galactus** · August 6th 2006, 09:28 AM

#3. $F(x)=kx$

$25=(20-10)k$

$k=\frac{5}{2}$

$\int_{0}^{5}\frac{5}{2}xdx$

**CaptainBlack** · August 6th 2006, 10:07 AM

Originally Posted by jaycas21

amount of natural gas is proportional to oxygen consumed. 24.0 kg of Oxygen is
consumed in burning 15 kg of gas how much air 23% oxygen by wieght is consumed to burn 50 kg

a.80 kg
b 345 kg
c. 31.3 kg
d. 135 kg

4.Which of the following expressions would help estimate the value of:
Which of the following expressions would help estimate the value of:
[IMG]

a.36
b.29.25
c.t
d.43

5.During each microsecond the current in an electric circuit decreases by 9.3%. If the initial current is 2.45 mA, what will the current be after 22 microseconds?

0.286 mA
0.496 mA
0.121 mA
1.24 mA

7.The sales S of a product as a function of the time t (in weeks) is given by S = [2300 (5t + 1)]/(2t + 5). Find the instantaneous rate of change of S with respect to t for t = 9 weeks.

125
51
900
100

Put new questions in a new post or better yet a new thread.

DONT edit an existing post deleting the original questions and replacing them
with new questions.

RonL

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