Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 Help Me ! » stuck on this cal 1 problem » 2008-09-16 02:03:15

kwinrow
Replies: 3

prove the statment using the epilson, delta defintion of limit:


lim     x^2+x-6/x-2=5
x→ 2

how do i go about solving this?

#3 Re: Help Me ! » help on problem » 2008-08-01 01:41:39

one other question, would I have to convert the answer to feet?

#4 Re: Help Me ! » help on problem » 2008-07-31 16:07:16

these for the values I got for t using the quadratic formula:


t=0, and t is approx. 18.07

then i plugged 18.07 into the first equation and got:


approx. 1124.41

this is right? is this the answer?oh yeah, what units would i use?

#5 Help Me ! » help on problem » 2008-07-31 09:08:28

kwinrow
Replies: 8

7.) If an object is thrown on the moon, then the parametric equations of flight are:

x=(vcostheta)t and y=(vsintheta)t-2.66t^2+h.

Estimate the distance that a golf ball hit at 88 ft. per sec (60 mph) at an angle of 45 degrees with horizontal travels on the moon if the moon's surface is level.


how would i go about sloving this?where would i start?

#7 Re: Help Me ! » i have a question for this problem » 2008-07-31 01:14:18

I have no idea how to finish this problem I am stuck on this step:

P=0.01(sin(443pit)cos(-3pit))

how do i finish this?when i graph it on the calculator i get nothing

#8 Re: Help Me ! » i have a question for this problem » 2008-07-30 07:58:12

so if i decide to plug in .44 as x i should get one single value right?

then using the order pair plot the dot?

#9 Re: Help Me ! » i have a question for this problem » 2008-07-30 07:13:07

ok so its:

0.005[sin(440pit)+sin(446pit)]=2sin(440+446/2)cos(440-446/2)?

then after this i get all terms to one side right? then graph?

#10 Help Me ! » i have a question for this problem » 2008-07-30 06:20:04

kwinrow
Replies: 8

Consider two tones with frequencies of 220 and 223 Hz and pressures P1=.005sin440(pie)t and P2=.005sin446(pie)t, respectively. Graph the pressure P= P1+P2 felt by an eardrum over the 1-sec interval [.15,1.15]. How many beats are there in 1 sec?

my work:

am I goin about this right?

P=.005sin(440pit)+.005sin(446pit)
P=.01sin(886pit)

now is this ready to graph in the interval [.15,1.15]?

or is there another step i need to do?

#11 Re: Help Me ! » Help with work » 2008-07-30 04:37:13

ok thanks a lot just needed clarification.

#12 Re: Help Me ! » Help with work » 2008-07-30 04:18:08

ok so this is what i am getting form you:


(in degrees)

arcsin(1/1.2)=56.44269024

now from here can i just go ahead and multiply the 2 or do I have to do something else first?

this is where i am confused

#13 Re: Help Me ! » Help with work » 2008-07-30 04:00:03

i confused why do u keep stating add or subtract 360 or 2pi any number of times

#14 Re: Help Me ! » Help with work » 2008-07-30 03:51:07

i was following the formula in the book and your answer is very similar to the format they used. This is what I got for my final answer:

3sqrt(u^2+1)/(u+1)

#15 Help Me ! » Help with work » 2008-07-30 03:09:18

kwinrow
Replies: 10

Basically i am stuck:


1.) cos(arctan(3/u))


my work:

theta=arctan(3/u)
tan(theta)=3/u

now what do i do?


2.) theta=2arcsin(1/1.2)

my work:

divided 1.2 into 1 and got:

theta= 2(.9851107833)

then do i multiply 2 into .9851107833?

am i doing this right?

Board footer

Powered by FluxBB