All Answers 358523 Answers

lower bound do you round down

Question 1 continued here.

Of course it is wrong......you didn't do the work did you?  I gave you the LOWER limit of perimeter as an EXAMPLE.....you just typed in the answer didn't you?

Lower limit for AREA  would be   15.75 x 5.15 =    .......    cm²

I showed how to obtain the LOWER limit PERIMETER as an EXAMPLE to you ....YOU were supposed to do the UPPER limit of PERIMTER.....

The two pyramids are similar to one another.

the lengths of the sides are in the ration 1:2

so the surface areas are in the ratio 1:4    (I squared them)

The surface area of the whole thing is 1200 if I subtract the area of the base it is 

1200-400=800

so the surface area of the top bit is 200

and the surface area of the base of the top bit is 100

So i think the surface area of the frustum is   (800-200)+400+100 = 1100

I have not put any huge amount of thought into this. So maybe it is not right.

I assume you can plug the answer in and tell me if it is correct?

Set Up:

All angles add up to 180.

x - 45 + 2x - 50 + x = 180

Solve for X

Wow...I just saw the speed of the train was given as 120 m/s

then   2 seconds to fully enter =  240 m train length

           3 seconds for back of train to exit = 360 m tunnel length

240/360 = 2/3     (same answer...I just wanted to use the given numbers) 

train takes 2 seconds to fully enter the tunnel      it still takes one more second for the front of train to reach the exit....and another two seconds for the back of the train to exit the tunnel

let's say it is travelling at 100 m/s

2 seconds to enter fully  =   2 s x 100m/s = 200m     this is how long the train is

3 seconds later the back of the train travels  300 m    and exits the tunnel      tunnel length = 300 m

length of train / length of tunnel   =   200/300  =   2/3

Even so, I appreciate the willingness to help.

the perimeter is wrong i dont really know

Two numbers have a difference of 3:  x - y  =  3

                                a sum of 31:        x + y  =  31

    adding down the columns:             2x       =  34

    dividing by 2:                                         x  =  17

You will still need to find y.

Example   LOWER bound 

   the dimensions COULD be  15.75   (rounds to 15.8)       and 5.15 (rounds to 5.2)

        lower bound for perimeter could be   2 x (15.75 + 5.15) = 41.8  cm

The wheel has a radius of 3 inches. 

Its circumference is 2·pi·3  =  6p  or about 18.85 inches

The wheel completes 7.3 revolutions in 6 seconds:

  7.3 revolutions = 7.3 x 18.85 = 137.6 inches

  7.3 revolutions in 6 seconds  =  137.6 inches / 6 seconds  =  22.9  inches per second

1000 is incorrect.

Except what makes absolutely no sense about the guest's answer is that base PQRS is 400 and the total is 170? BRUH

Hi Jenny,

You have not used the 6.2 radians per second bit.

Your answer assumes 1 radian /sec

Take a proper look at my method.

It is seriously worth understanding.

F = 24d =  71

F + 22d  =  68    Subtract this equation from the first

        2d = 3

          d = 3/2  =  $1.50 / day      now use this value of 'd' in either one of the equations to compute 'F' 

No I haven't heard of that.

Yes, nurses just type in the parameters and so long as they enter it properly the machines do the calculations.

There is really no problem with this, it is no different than an engineer using an advanced calculator. 

Nurses do have the 'formulas' drummed into them and intelligent nurses do work them out and remember how to use them.

It is a bit like learning the logic of language rather than the logic of maths. The rules must be learned and followed but the logic behind the rules is a bit hazy.

I used to tell my kids that they needed to be able to work problems out themselves as they may find themselves in a war or third-world situation where facilities were much more basic. 

ONE revolution is 2 pi radians

3.6 rev / 6 s   x   60 s / /1 min     x   2 pi rad /rev   = 3.6 /6     x 60    x   2 pi  = ......... Radians/min    (leave 'pi' in your answer )

wouldnt you do 1.6* 60 seconds = 84 radians

then 84/2pi ? = 15.3 ?

Answer for problem #2:

Part a) Using the upper bounds of the lengths (87.35 cm and 51.85 cm), we get 4529.0975,

            when rounded, give 4530. cm².

Part b) Using the lower bounds of the lengths (87.25 cm and 51.75 cm), we get 278 cm.

Yes...I've seen nuurses make mistakes when a curve is tosses at them and a drug all of a sudden comes with a different concentration/strength.  They have infusion pumps now in which you enter all of the parameters and it will calculate the infusion rate for you.....I think they just do that and assume they got it all correct wiithout knowing the method the infusion rate is calculated...kinda scary, but they woud often ask me if everything looked 'OK"......

   Perhaps you heard of the 'rule of sixes'   'point sixes'   etc when mixing or compounding infusions so that the ml/hr displayed on the pump was

mg/kg /min etc ? 

Hi Impasta,

I agree that guest did sound abrupt, however, you made a statement and guest asked you to put your typing fingers where your mouth was.

It is reasonably obvious that you do not know how to answer the question yourself so you were not in a position to judge if Max's answer was elegant or not. 

I think Max's answer was very impressive. 

I don't understand --

-- if line m has equatioin  y = 2x - 5

-- if line n has equation    y = x + 22

they won't be parallel because they don't have the same slope (the slope of m is 2 while the slope of n is 1).

Do you mean that they aren't parallel and you need to know where they intersect?

cos(a - b)  = cos(a)·cos(b) + sin(a)·sin(b)

Since tan(a)  =  -12/5  and is in quadrant II, sin(a) = 12/13  and  cos(a) = -5/13

  (It's a 5-12-13 right triangle, with x-value negative and y-value positive.)

Since cos(b)  =  3/5  and is in quadrant IV, sin(b)  =  -4/5.

  (It's a 3-4-5 right triangle, with x-value positive and y-value negative.)

Place these values into the formula to get your answer.