Thread: review sheet

Would this make sense for the first one?

h=48t-16t²
h=(-16t²+48t)
h=-16(t²-48t) >>>> -48/2=-24²=576
h=-16(t²-48t+576-576
h=-16(t-24)²=9216
Vertex: (24, 9216)
So max height is 9216m

Thanks guys!

Originally Posted by fix23

Would this make sense for the first one?

h=48t-16t²
h=(-16t²+48t)
h=-16(t²-48t) >>>> -48/2=-24²=576
h=-16(t²-48t+576-576
h=-16(t-24)²=9216
Vertex: (24, 9216)
So max height is 9216m

Thanks guys!

you are right in that you must find the vertex, however, you did it incorrectly. work on completing the square. or simply use the vertex formula.

the -coordinate for the vertex of a parabola of the form is given by:



you can use that to find the t-value for the max height, and then plug that into the h formula to find the max height.

if you really want to go the completing the square way (which i don't recommend for questions of this type), just say so, and we'll go through it

Originally Posted by fix23

ok, so im aloud to make a cheat sheet for my test tomrrow. our teacher has said that these examples will be or be like the ones on the test... im gunna admit, im not really good in math, and my mark could be in jepardy. i would be very upset aswell as my parents if i failed. this test is a biggy, so all the help i could get, please speak up it would help greatly.

ok so here are the questions he said would be or close to be on the test.

1) On plannet claire, the hegiht, H- meters of an object fires up from ground at 48m/s is described by H = 48t -16t^2. t = time in seconds since object was fired. Determine max height of the object, the times it is 32m above ground and the time it hits the ground.

B) What is the Max height of the object?

i addressed this part already

c) At what times is the object 32m above the ground of planet claire?

just plug in h = 32 and solve for the t-values

D) What time did the object hit the ground?

solve for the times where h = 0, and pick the appropriate time

Originally Posted by fix23

2)[/B] TI - 83 scatter plot and exponential equation steps.
N =
I% =
PV =
PMT =
P/Y =
C/Y =

B) Use TVM to calculate what $2500 deposited for 3 years at 7% compunded monthly. Fill in the values on the TVM screen.

3) Differences between savings account and G.I.C. and why it's better to use either option.

4) Whats a Credit rating and what factors effect it.

can't help you with these

5) When is it better to use sine Law instead of Cosine Law? and why?

we use the cosine rule if:

- we have the length of three sides of a triangle and we want to find one of the other angles
- we have the length of two sides of a triangle and the value of an angle not bounded by the two sides, and we want to find the third side, which we can use to find the other angles...
- we have the length of two sides of a triangle an the angle bounded by the two sides, and we want to find the other side


we use the sine rule if:

- we have the length of two sides and an angle not bounded by the sides and we want to find the other angle not bounded by the two sides
- we have the value of two angles of a triangle and the length of one side opposite one of the said angles, which we can use to find the length of the other side opposite the other angle
- we have the value of all three angles of a triangle but only one side, we can use the sine rule to find the other side


...i think that covers everything. you can google: "sine rule", "the law of sines", "cosine rule" and "the law of cosines" for more info

Thanks alot!... ill be marking this down. i appreciate it alot!

thanks

Originally Posted by fix23

6) Sampling techniques (Random, Stratified, clustered, Convienence, Voluntary) is used to gather unbiased data. which is the best one and why?

7) a)

Time : 0/1/2/3/4/5/6/7/8/9
Temp: 50/38/28/22/16/10/9/7/5/3

Linear, Quadratic, or Exponential- what is the best for this problem and why?

can't help you here. statistics ios not one of my strong fields

Use TI - 83 to find the best Exponential equation (what is this??)

an equation of the form , where is a constant, is called an exponential equation. of course there are more general forms to the equation. like or something

to fit the data. round to two decimal places. Explain.

B) Predict what the temp will be after 7.5 minutes

this we can tackle after you take care of the first question. it is simply a matter of plugging in time = 7.5 min and solving for temp in the equation you developed

8) Draw a scale "Net" of the object in class

9) A) Design a Clear unbiased questionnair to gather input on restricting one lane of a 3 lane highway to being a car - pool and bus, lane only. You are trying to discover if people will support is as a way to reduce traffic congestions.

10) An American university recorded the following data from a random sample of 100 light bulbs - This shows the total number of bulbs burnt out after reported days.

DAY: 1/7/14/21/28/35/42/49/56/63/70/77/84/91/200
Bulbs Burnt: 3/20/36/49/60/67/75/79/83/86/89/91/93/95/100

i hate statistics...

A) Is this discrete of Continuous Data?

it is discrete since it has a countable number of "inputs" and "outputs", and it usually includes the notion of things being finite as well

B) Create a tally chart for the life in days of the bulbs (eg: 3 bulbs lasted 1 day, 17 bulbs lasted 7 days, etc, etc)

C) Sketch an appropriate gragh - either a histogram or bar chart to illistrate the data B)

this seems straight forward

D) What is experimental probability that a light bulb will be burned out after 4 weeks?

E) Using any mathod and/or technology tought in class, find the average lifetime of the bulbs in the experiment.


Any help contributed would help GREATLY!!! you dont even kno how important this is to me. Thank you so much in advance.

If there is somthing i could do, please let me know and ill do it!
please try and explain the things that are required

Thanks a ton!

-Fix23

that's all the help i can give

Thanks a ton, this should help me alot!! for tomrrow.

If anyone knows the things that Jheven didnt recognize could you please give it a shot.

again, thanks a ton Jheven!