I Need Help With This Question Pls Its About Lmits

Help me answer my math question? what does it mean by nearest centimetre?

Qn: Sergio's height is 142cm, to the nearest centimetre. Complete the statement about the limits of his height.
Ans ...............................cm< height<....................cm

Help me in this questions ... plssss?

A number 14 copper wire has a diameter of 1.628 mm.
1) Calculate the resistance of a 34.0 m long piece of such wire.
(Use 1.72×10-8 Ωm for the resistivity of copper.)
2) For safety, the National Electrical Code limits the allowable amount of current which such a wire may carry. When used in indoor wiring, the limit is 15.0 A for rubber insulated wire of that size. How much power would be dissipated in the wire of the above problem when carrying the maximum allowable current?
3) What would be the voltage between the ends of the wire in the above problem?
4) What is the current density in the wire when it is carrying the maximum allowable current? (Current density is the current in the wire divided by the cross sectional area of the wire.)
5) What is the drift velocity of the electrons when the wire is carrying the maximum allowable current?
(The density of electrons in copper is 8.47×1028 m-3.)

Need help on Epsilon and Delta limits.?

I never think a calculus student is "retarded" which is a politically
incorrect, so I will say I never consider calculus students
mentally challenged. If you have made it calculus, you have
passed several algebras, geometry and precalculus. My poorest
algebra students need a calculator to do 3 times 5 so even an F+
student in Calculus has some competance!!

These sons of guns are hard and have been hard for years.
Even in 1975 , EVERYBODY in our class missed the delta epsilon
problems on the first calculus midterm in my college freshman Calculus class
making the highest grade in the class 89% .

Nevertheless, they are not impossible. You have to look at and write the
definition of the limit EACH time, namely

lim..f(x) = L
x→a

If, and only if, for EACH ε>0 {no matter how small}
there exist a δ>0

SUCH THAT

whenever 0<|x-a|<δ

then |f(x-a)|<ε

To show that this is true FOR
for EACH ε>0 {no matter how small}

We literally, when doing one of these proofs, have to
FIND an expression for δ that is a function of ε

the epsilon is on the Y axis and the delta is ON
the x axis.

For big epsilons,you can always find a delta so they are not even
necessary to consider. For that reason, they usually start these
proofs by saying let delta = minimum(1, some function of ε)

then show that applying f(x) function rule to any quanitity in
interval

(x-δ,x+δ) will give a value to f(quantity) that is in the interval

(f(x) -ε ,f(x)+ε )

Since your graph is given, it is EPSILON that is 0.2 and
given to you, not DELTA.

Now look on the x axis to determine DELTA.

It is the SMALLEST of the ABSOLUTE VALUES { that's positive}
of the two deviations from x=2.

Calculate them both

10/3 minus 2 = 3 1/3 minus 2 = 1 1/3
and

2- 10/7 = 14/7 - 10/7 = 4/7

The smallest is the 4/7.

We use the smallest, because on the other
side of 2, if x is within 4/7, then it is certainly within
the bigger margin of 1 1/3.

Therefore if |x-2|< 4/7 as value of δ

then

|f(x) - 0.5|<0.2 = ε

Limits of accuracy and directed numbers,help needed !?

Hi,I am stuck with these sums,pls if you can help me,I will be able to continue with the rest.
Limits of accuracy -

1. Crates of video cassettes are labelled '300 kilograms to the nearest 50 kgs.'
A plane can carry 19000 kgs of cargo.
How many crates of video cassettes could it carry safely?

>> I have tried this by finding the least & most possible values of 300,after that I dont get it.

2. Can you tell me if this is right ?
The side of an equilateral triangle is given as 8cm,correct to the nearest cm.
What is the least possible length of the perimeter ?

Ans. 7.5 << 0.5 - 8 + 0.5 >> 8.5
Answer = 7.5cm .......how do I this to the nearest cm ?? It will be 8,wouldnt make any sense.

Directed numbers -

3. The sea level at low tide is -2.35 metres. What is the sea level when it is 1.28 metres above this?

a. Is it > -2.35-1.28 = -3.63 m OR
b. Is it > -2.35 x 1.28 = =3.008 OR are both of them wrong ?

4. The sea level at high tide is 3.08 metres.What is the sea level when it is 1.28 metres above this?

Ans. 4.29 - 3.08 = 1.21m >> is it right ??

Pls say honestly,don't just say its right even if you dont know,because I am going to get checked tomorrow,then i will choose the best answer according to that.
Thank you :)

Help calculus limit pls?

lim (x - 5)/(4x + 3)
x -> -2

As long as substituting the value results in a non-zero denominator, just plug in the value x = -2 to solve the limit.

(-2 - 5)/(4(-2) + 3)
(-7)/(-8 + 3)
-7/(-5)

7/5

Calculus limit help pls?

i have confusion regarding left limit and right limit

suppose f(x)= x+9 find limit of f(x) when x--> 3

in my textbook its written take x = a+h , the concept isnt clear to me
so when a approaches 3 h -->0 thats clear to me

but in case of right limit a-h its also written
that h-->0 but in this case how is h approaching zero , isnt h increasing ? to get closer to a? in a-h
i believe higher the value of h , closer a gets to 3, but i am wrong

can u explain everything thanks for ur effrts in advance