Mathematics-SCMATH.COM

I can't find this derivative!?

RAWRitsa... — 2008-03-09 17:08:33

-4x - 3.78
-----------------
(2x - 7.29) ^ 3

I need to find the derivative of this and I can't do it >_> i spent so long on calculations and it was wrong

How do you input scientific notation on a calculator?

james t — 2008-03-09 15:51:07

i have a TI-84 plus graphing calculator and i put in this equation with scientific notation in and it says error?

the equation i put in was:
6.67x10^-11 (1000x1000) / (0.3+0.3)^2

how do i put this equation in correctly to the right answer without getting an error? help :(

Math help!!!?

trcolvar... — 2008-03-09 15:40:38

In 1994, the life expectancy of males was 69.9 years. In 2001, it was 73.4 years.Let E equal the life expectancy in year t and let the t represent the number of years since 1994. Create the function- E(t)=(Blank)t+(Blank)
Use the function to find out the life expectancy in 2004. Round both to the nearest tenth.

Box curve sketching?

RAWRitsa... — 2008-03-09 14:50:11

You are supposed to design a rectangular box, open at the top and with a square base, that is to have a volume of exactly 2048 cm3. If the box is to require the least amount of material, what must be its dimensions?

Let x be the length and the width of the box and let y be the height of the box. Then the volume of the box is given by V= (x^2)y and the surface area is A= x^2+4xy . The problem is to find x and y to minimize A .

First we express y in terms of x and V to get y = ___
This implies that the surface area is given in terms of x only by ___. It follows that dA/dx= __ and that the critical value is x= ___

Since d2A/(dx2)= ___

for all x > 0, by the second derivative test, it follows that the surface area function has a relative ___ when x = ___ cm.

Calculus help!?

mily — 2008-03-09 14:25:58

can someone integrate this problem for me.. showing the steps,

∫(lnx)^2 dx

What is $21.95 - 26% off?

Seven — 2008-03-09 14:20:56

So it is super early and honestly i am terrible at maths.
Thanks

Find the x-intercept: y=x^2-x+2?

yeahyeah... — 2008-03-09 14:12:44

Solve the following equation for x:?

yeahyeah... — 2008-03-09 14:11:13

(8/x) minus (3/x^2) = -6

Solve the following equation for x: x^2+6 = 30?

yeahyeah... — 2008-03-09 14:09:51

x = + 24^0.5, x = – 24^0.5 (standardly, x = +/- 2*6^0.5)

Try it this way and see how many answers you get:

x^2 + 6 = 30 subtract 30 from each side
x^2 + 6 - 30 = 0 calculate
x^2 - 24 = 0 factor: x^2 - a^2 = (x + a)*(x - a)
(x + 24^0.5) * (x - 24^0.5) = 0 solve for possible x's
x = + 24^0.5, x = – 24^0.5

So, both square roots, not just the positive one!

Use the distance formula to show that each set of points describes an isosceles triangle?

yeahyeah... — 2008-03-09 14:02:01

Use the distance formula to show that each set of points describes an isosceles triangle (a triangle with two sides of equal length).

(-2,4), (2,7) and (5,3)

I have never seen an algebra problem like this one. Please help me to evaluate it, if possible.?

yeahyeah... — 2008-03-09 13:54:39

The is a square root symbol and inside if it is a -16. There is also a small 4 in the above the V part of the square root. So it doesn't look like 4sqrt-16, but rather sqrt with a small 4 above it and then a -16 in the square root. Does anyone know how to do this problem? I hope I explained it okay! Thanks for your help in advance everyone!!

Which is greater and why?

Smooch — 2008-03-09 13:53:34

An infinitely tall stack of 1 inch cubes, two such stacks or an infinite number of such stacks?

Finding derivatives and critical points?

RAWRitsa... — 2008-03-09 13:47:21

g(x ) = (2x - 2.7)/ (2 x -7.29 )^2

I can't find the critical points of the derivative of this.
Also, how can i find the point of inflection and the second derivative?

This is a hard one! Subtract and add as indicated and write the results in simplest form?

yeahyeah... — 2008-03-09 13:35:08

(-3-2x^2)/(-x^2-9x+20) minus (4x^2+2x+1)/(x^2-9x+20) plus (2x^2+3x)/(x^2-9x+20)

Thanks for any help on this tough one everybody!!

Subtract as indicated and write the results in simplest form.?

yeahyeah... — 2008-03-09 13:30:16

2x/(x-3) minus 6/(x-3)

Write the fraction in simplest form:?

yeahyeah... — 2008-03-09 13:27:33

(14x^2 y) / (-21xy^4)

Calc help please?

Josh N — 2008-03-09 13:20:24

In this problem you will rewrite the rational function (8*x+1)/(25*x^2+10*x+18) in a form which will permit easy antidifferentiation.

(A). By completing the square write the quadratic 25*x^2+10*x+18 in the form (a*x+b)^2+c where a, b and c are constants. Enter the expression in the exact form as your answer (sqrt(5)*x-2)^2+31. You must enter multiplication with *.

(B). Use the substitution v = a*x+b with a and b as in the previous part, to rewrite (8*x+1)/(25*x^2+10*x+18) with a denominator of the form v^2+B where B is a constant. Your answer should be a rational function in v, (2*v-4)/(3*v^2+7).

(C). By making the substitution u = v/sqrt(B), rewrite the rational function of v from the previous part as a rational function of u with denominator u^2+1. Your answer should be a rational function of u, e.g., (3*u-2)/(u^2+1).

Thanks guys i'm having big troubles with this on my homework. Any explanation would be greatly appreciated.

Analytical trigonometry help?!?!?

umm...ok... — 2008-03-09 12:56:55

how do you do this??

sin(theta)+sin 3(theta)/2sin2(theta)=cos(theta)

i have no idea how to this. HELP!!

What is the range of these salaries?

turkeyfa... — 2008-03-09 12:31:50

$21,750., $33,500., $18,900., $22,965., $30,080., $47,250., $37,750., $46,500.

CHOOSE FROM THEANSWERS:
$24,750.
$25,500
$27,600.
$28,350.

AND EXPLAIN WHYY.

Probability?? easy?? 10 pts for first right answer?

arnav c — 2008-03-09 12:09:28

Jar contains 6 red marbles and 10 green marbles. A marble is picked randomly and then REPLACED. This is performed 11 times. What is the probability of picking 4 red marbles and 7 green marbles?

please show the work

thanks a lot!

Curve sketching Box question?

RAWRitsa... — 2008-03-09 12:06:48

You are supposed to design a rectangular box, open at the top and with a square base, that is to have a volume of exactly 2048 cm3. If the box is to require the least amount of material, what must be its dimensions?

Solution: Let x be the length and the width of the box and let y be the height of the box. Then the volume of the box is given by V= ___ and the surface area is A= ___. The problem is to find x and y to minimize ___.

How do we figure out the blanks?

First blank can be:

x^3,
x^2(y),
y^2(x),
xy

2nd Blank:

x^2 + 4xy,
(x^2)y
x^2 + xy
xy

and Third blank is either area or volume.

Thanks!

Vector: Find the equation of the plane passing through the point..?

iryne_be... — 2008-03-09 12:03:33

Find the equation of the plane passing through the point (1,1,1) and perpendicular to planes 3x - 2y + 5z = 5 and 4x - 3y - z = 7

I need help with a derivative and integration problem.?

alexdima... — 2008-03-09 11:56:10

First Question.
If dy/dx = xy^2 and x=1 when y=1 then y= ?

Second Question.
I want to integrate the function x/(x+1)

I need very detailed responses so the more detail you can show the better. Thank You!

Quick math B help please!! (=?

yourstru... — 2008-03-09 11:19:15

im studying for my test and im unsure on how to do these two problems. when you answer, can you please say how you got it?
1. solve the given equation. answers should be left in radical form.. x(x+6)= -4
and..
2. there is a question that has h(t)=-16t^2+30t+6 would the h(t) be considered y? or would you have to divide by t to get the h alone?
thanks for the help! (=

Algebra 1?Check my answers?

♥I Love David Archuleta♥ — 2008-03-09 11:08:51

1a. In construction, floor space must be given for staircases. If the second floor is 3.6 meters above the first floor and a contractor is using the standard step pattern of 28 cm of tread to 18 cm of rise, then how many steps are needed to get from the first to the second floor and how much linear distance will need to be used for the staircase?

Number of Steps- 20 steps
Linear Distance- 5.6 meters?

2b. How long would a railing be that was parallel to the steps in problem (1a)?

Railing- about 633 cm long?

ARE THESE CORRECT?

Probability Question?

KaLi E. — 2008-03-09 11:00:47

If you have 3 4-sided dice, what is the Probability of getting the number 4 on all 3 dice at the same time?

Hard algebra word problems?

gappytra... — 2008-03-09 10:46:15

1.Hockey teams’ receive 2 points when they win and 1 point when they tie. One season, a team won a championship with 56 points. They won 10 more games than they tied. How many wins and how many ties did the team have?

2.Snoops log can convert logs into either lumber or plywood. In a given day, the mill turns out twice as many units of plywood as lumber. It makes a profit of $30 on a unit of lumber and $45 on a unit of plywood. How many of each unit must be produced and sold in order to make a profit of $12,360?

Snoops lumber must produce and sell ? units of lumber and ? units of plywood to make a profit of $12360.

3.Bayside insurance offers two plans. Under Plan A, Gisele would pay the first $190 of her medical bills and 40% of the rest. Under Plan B, Giselle would pay the first $230 of bills, but only 20% of the rest.

For what amount of medical bills will Plan B save Giselle money? (Assume that her bills will exceed $230)
Round to the nearest whole number

Relative extrema?

RAWRitsa... — 2008-03-09 09:53:18

I need to find the absolute extrema if they exist and the values of x at which they occur and specified domain.

f(x) = (1/3)x^3 - (1/2)x^2 - 6x + 3; [-4, 4]

Can you please explain how you did each step too? I am really confused for questions like these and I want to be able to solve them and not just know the answer and steps which are required.

What is the answers?

sportsma... — 2008-03-09 09:53:00

7x + 5y = 28
7x + 3y = 70

2x - 3y = 30
5x - 3y = 60

4x + 5y = 35
2x + 3y = 19

7x + 4y = 190
1x - 4y = 18

3x - 4y = 20
5x+ 3y = 14

Whats the answer please help?

sportsma... — 2008-03-09 09:36:52

5x + 3y = 48
4x + 3y = 60