Science & Mathematics - 15 August 2007

a) Find an expression for dy/dx

b) Find the gradient of the tangent to the curve at the point
(-2,-1).

c) Find the equation of the normal to the curve at the point
(-2,-1)

Please answer all 3 qs its urgent

2007-08-15 22:02:51 · 2 answers · asked by Anonymous in Mathematics

2007-08-15 22:01:26 · 2 answers · asked by gloria g 1 in Engineering

2007-08-15 22:00:47 · 12 answers · asked by Anonymous in Weather

2007-08-15 21:59:43 · 10 answers · asked by Anonymous in Biology

Use the rules of differentiation to find the derivatives of the following function. Simplify terms wherever possible, but it is not necessary to factorise and then cancel any of the expressions.

2007-08-15 21:52:47 · 4 answers · asked by Anonymous in Mathematics

Use the rules of differentiation to find the derivatives of the following function. Simplify terms wherever possible, but it is not necessary to factorise and then cancel any of the expressions.

2007-08-15 21:50:32 · 2 answers · asked by Anonymous in Mathematics

Use the rules of differentiation to find the derivatives of the following function. Simplify terms wherever possible, but it is not necessary to factorise and then cancel any of the expressions.

2007-08-15 21:42:38 · 4 answers · asked by vanisha j 1 in Mathematics

that would mean we were at the center of the universe if the universe were expanding at the speed of light

2007-08-15 21:34:30 · 7 answers · asked by Anonymous in Astronomy & Space

2007-08-15 21:32:21 · 26 answers · asked by Andy D 1 in Astronomy & Space

1. The empire state building is 1472 ft. high.
a. how long will it take an object drop from the top of the
building to reach the ground??
b. what would an objects final velocity be??

2. A body falls freely from the rest. FIND:
a. the acceleration
b. the distance that falls 3s
c. it's speed after falling 70m
d. time required to reach the speed of 25m/s
e. time taken to fall 300m

2007-08-15 21:11:45 · 3 answers · asked by Gray_Matter 1 in Physics

hi all, this question is actually in one of the exam practise papers for my younger brother who's only 9. I don't know if i should be worried but i came up with the answer (320) using a 6-step long algebraic method.
As i am tutoring him, do any of you guys know an easier, simpler, way to solve it so i can help him understand better? He hasn't learnt algebra yet.

Here's the question:
"After Denis spent $160 of his pocket money on food, and 3/4 of the remaining money to pay his mobile phone bill, he had 1/8 of his total pocket money left. How much pocket money did Denis have at first?"

Thank you so much! Also just out of curiosity, does anyone else think this maths problem isn't so easy for a 9 year old? (or am i just a little daft?)

2007-08-15 21:09:47 · 11 answers · asked by Anonymous in Mathematics

Ok, last one guys ^^

Thanks for all your help so far!

Ok, here it is:

A sail that is in the shape of an isosceles triangle has a vertex angle of 38 degrees.

The angle is included by two sides, each measuring 20 ft. Find the area of the sail.

Please refreash my memory on what an isoceles triangle and wish me luck on my test tommorow! I'm going to need it!!!

Thanks again everyone ^0^

2007-08-15 21:05:39 · 3 answers · asked by Rebirth _2007 1 in Mathematics

Hey, I'm in a competition and I'm trying to identify certian animals from Tanzania. I would really like your help if you could give it. :)

http://img254.imageshack.us/img254/3315/10739086ee4.jpg

http://img254.imageshack.us/img254/1829/66701155vx5.jpg

http://img254.imageshack.us/img254/6610/89586858sj9.jpg

http://img254.imageshack.us/img254/408/72999713sh8.jpg

http://img254.imageshack.us/img254/6353/14td7.jpg

http://img254.imageshack.us/img254/9144/16bg8.jpg

Please help me by Thursday night please :) Thanks

2007-08-15 21:04:30 · 3 answers · asked by Anonymous in Zoology

2007-08-15 21:01:33 · 3 answers · asked by aussiedeb 1 in Geography

Hi. Is anyone knows where to find info about material, equipment and process to produce a correction tape? Thanks.

2007-08-15 21:01:27 · 1 answers · asked by stevenfoong 1 in Engineering

hi all!
can you please help me out with some maths questions and how to work them out? here they are...

1) Between which two consecutive whole numbers does square root(8) lie?

2) Factorise by grouping
xy+2x+3y+6

3) Is the variable "milk production per cow"
A-ordinal
B- Nominal
C- Continuous
D- Discrete

4) Lisa had a box of apples. She gave 1/3 of them to henry and 1/4 of the remainder to Alex. If there were still 30 apples left, how many did she have at the start?

Thanks to all who attempt to answer.

2007-08-15 20:55:04 · 5 answers · asked by i love...love 2 in Mathematics

Please explain this question is you can...

Ok, here goes:

An airplane leaves its airport on the east coast of the US and flies in a direction of 085 degrees.

Because of bad weather, it returns to another airport 230 km to the north of it's home base.

For the return trip, it flies in a direction of 283 degrees.

What is the total distance that the airplane flew?

Thanks for you help!!!!!!!!

2007-08-15 20:53:01 · 5 answers · asked by Rebirth _2007 1 in Mathematics

thanks! (:

2007-08-15 20:51:57 · 3 answers · asked by Ocean Princess 1 in Botany

Why can't we just zoom in more?

2007-08-15 20:47:45 · 6 answers · asked by Anonymous in Physics

Every employee can receive an additional 20% off of the lowest price of an item in a departmental store. if an employee purchase a dishwasher at 15% off sale, how much will he pay the dishwasher if its original cost is Rs.450? - please fetch me the answer with working i.e., the way to solve this...

2007-08-15 20:45:28 · 4 answers · asked by vinu 1 in Mathematics

Please bear with me, I just have a few more questions to ask!

I'm so grateful for any help you can give me =)

Ok here goes:

An airplane leaves an airport and travels for 100 mi in a direction of 300 degrees. How far north of the airport is the plane then? How far west?

Thank you!!

Please explain as much as possible =)

2007-08-15 20:39:12 · 5 answers · asked by Rebirth _2007 1 in Mathematics

i have always wondered......i mean i know they communicate, but do they actually have like conversations....? for instance do they talk about the weather, things that are on their minds, or the food that they just ate......?

2007-08-15 20:30:34 · 11 answers · asked by hey123 4 in Zoology

2007-08-15 20:24:55 · 9 answers · asked by Anonymous in Zoology

what are the similiraties and differences between these two islands?

2007-08-15 20:20:50 · 5 answers · asked by Anonymous in Geography

Can anyone please help me with this Trig question?

I'm cramming for a test tommorow morning and I'm lost...

ok, here goes:

In Extremely large forests, it is not cost effective to position forest rangers in towers or to use small aircraft to continually watch for fires. Since lightning is a frequent cause of fire, lightning detectors are now used instead.

A detector at point Q is situated 15 mi west of a central fire station at point R.
The bearing from Q to where lightning hits due south of R is South37.6(degrees)East.
How far is the hit from point R?

Please explain as much as possible*

Thanks a million!!!!!!!!

2007-08-15 20:17:59 · 5 answers · asked by Rebirth _2007 1 in Mathematics

Please also provide another reaction with benzoic acid, although I have a feeling that the mechanism is the same. I know that there will be a formation of some colored complex, however, I don't know the formula to this. Answers are greatly appreciated. Thanks!

2007-08-15 20:13:27 · 2 answers · asked by DrJamerlan 2 in Chemistry

Given the solution is prepared by boiling 4g of hydroxyammonium sulphate, (NH3OH)2 SO4 per dm3 with excess iron(III) ammonium sulphate and dilute sulphuric acid.

2007-08-15 20:12:40 · 1 answers · asked by teokz2002 1 in Chemistry

My diesel injector keeps coking and clogging, distorting the spray pattern, could ultrasonic energy keep the coked particles from clogging the nozzle?

Diesel generator operation

2007-08-15 20:11:58 · 4 answers · asked by DH 1 in Physics

Based on evolutionary theory humans could be related to simians in many ways. If this is true why is it that when a human does not cut his/her head hair, it will continue to grow? Why is it that monkeys do not need to cut their hair? It seems that their hair has a determinate final length.

2007-08-15 20:11:27 · 6 answers · asked by Noncyclicphotophosphorylation 2 in Biology

This is the idea that the past itself is an impenetrable wall, and that we can only access it mentally. Other energies cannot enter, so they bounce of of it. This makes time travel into the elasped past impossible as well...

2007-08-15 20:07:36 · 3 answers · asked by sassychickensuckerboy 4 in Physics