Mathematics - 22 October 2007

I need to find the trapezium with the maximum area which is in a semicircle, using differentiation. The big base of the trapezium is the diameter of the semicircle (2R) and the other two vertices on the semicircle.
What I have to do, is to express the area A=[(b1+b2)h]/2 in R, then find the first derivative and then the stationary points.
Any idea how to express all the variables of the formula in R?

2007-10-22 07:33:22 · 3 answers · asked by andymathematics 1

1x + 1y + 5z = 9
2x + 3y + 9z = 17
-1x + 3y - 8z = -11

I got this far:

1 1 5 9
2 3 9 17
-1 3 -8 -11

2007-10-22 07:29:49 · 4 answers · asked by Byron 1

2x + y = 6
x² + y² = 20

2007-10-22 07:27:51 · 11 answers · asked by Leo 3

express in the form a(x-h)^2 + k

2007-10-22 07:19:05 · 2 answers · asked by Anonymous

49^2-9=0

b^2-5b=0

a^2-9a+20

0=v(v+4)

2007-10-22 07:13:57 · 10 answers · asked by Belki C 2

These problems are just totally throwing me for a loop! I am terrible at math and don't know why the person in charge of classes assigned me to this.

5 - 9w = 23
17 = 7 + 8y
-2.5d - 32.7 = 74.1

Thanks!

2007-10-22 07:04:46 · 7 answers · asked by jacobsbeffie 1

2007-10-22 07:04:30 · 11 answers · asked by robinmorton1993 1

Why is x the letter everyone uses? It is the main variable, it is an axis, why x? Anyone with little tidbits of knowledge know the answer?

2007-10-22 06:58:55 · 6 answers · asked by Lorianna 2

2007-10-22 06:53:51 · 11 answers · asked by Anonymous

Find two quadratic unctions with zeros x= -1 and x=2.........I already found one of the equations which ended up being x^2-x+2 but im not sure on how to find the second equation
Thanks you math people...I'd be lost with out yous

2007-10-22 06:50:54 · 3 answers · asked by ELECTRA 1

A lattice point on the xy-plane is any point (p,q) where both p and q are integers.
Suppose you have a line passing through the origin with irrational slopeExamples of lattice points are the points (1,2) (1,3) (1,4) (2,2) (2,3) (-2,3) (45,56) (10000, 10003) (-34,55). Examples of points which are not lattice points are (1/2, 3) (4,5/6) (√2, 5) (pi,4). Explain why such a line can never pass through a lattice point.
This is one of my math questions but i cant seem to figure it out?!

2007-10-22 06:32:19 · 3 answers · asked by i 1

2007-10-22 06:32:15 · 2 answers · asked by Ladan T 1

Given that the mass of block A is 8.30 kg and the coefficient of static friction between block A and the surface on which it rests is 0.340, what is the maximum mass block B can have and the system still remain in equilibrium? (Both blocks are at rest).

http://i214.photobucket.com/albums/cc30/bkoz319/06-33.gif





Thanks sooo much for your help!! God Bless!

2007-10-22 06:27:34 · 1 answers · asked by CrimsonRider 1

This is a typed out pic, http://smg.photobucket.com/albums/v180/Wazuka/?action=view¤t=mathprob.jpg
if it is confusing....

Thanks for the help...

2007-10-22 06:26:06 · 6 answers · asked by Molly❀ 3

Showing all your working, solve this simultaneous equation:
3x -4y = 23
5x +2y = 21

2007-10-22 06:26:00 · 7 answers · asked by 29chris29 1

The radius of a sphere is increasing at a rate of 4 mm/s. How fast is the volume increasing when the diameter is 100 mm? Evaluate your answer numerically.
mm^3/s

A street light is mounted at the top of a 15 foot tall pole. A man 6 ft tall walks away from the pole with a speed of 4 ft/s along a straight path. How fast is the tip of his shadow moving when he is 40 ft from the pole?
ft/s

2007-10-22 06:22:16 · 3 answers · asked by Anonymous

radicands represent positive real numbers.


cube root(27) - 5*cube root(8)

2007-10-22 06:20:10 · 2 answers · asked by Anonymous

2007-10-22 06:12:21 · 4 answers · asked by Flamezz 5

If p and q are distinct primes and gcd(a,p*q)=1 and
n=lcm(p-1,q-1), then show that a^n = 1(modulo p*q).

Okay, we have gcd(a,p)=gcd(a,q)=1 since p and q are distinct. Then by Fermat's Theorem,

a^(p-1)=1 (modulo p) and a^(q-1)=1 (modulo q). Then how can we proceed?

2007-10-22 06:10:35 · 1 answers · asked by Anonymous

Let cos alpha - (sqroot 5) / 5: 0 < alpha < pi/2; sin beta = -4/5: -pi/2 < beta < 0. Find the exact value of the following:


c) sin (alpha / 2)

d) cos(2 beta)

please help and explain, keep getting different answers, thanks

2007-10-22 06:07:39 · 1 answers · asked by mathhelpmee 1

given:

gamma=40
a=3
b=4

Have to find:

Beta , alpha, c

please help me and explain this to me step by step, thanks my book sucks!!

2007-10-22 06:00:42 · 4 answers · asked by Anonymous

2007-10-22 05:56:49 · 3 answers · asked by Anonymous

it's really simple but i just need to know what it is, helpppp a;lskjdfl;kjad

2007-10-22 05:56:17 · 7 answers · asked by Katie 4

2007-10-22 05:51:00 · 6 answers · asked by jimmy n 1

I have seen people answering using square root symbols, integral symbols etc. Do you need a special key board? Do you have to use control keys or do you have to download fonts? How is it done?

2007-10-22 05:50:02 · 2 answers · asked by cidyah 7

2007-10-22 05:49:10 · 8 answers · asked by Anonymous

If you have a typical lock that takes 3 numbers to open it. 1 to the left, 1 to the right, 1 to the left (you guys know what i'm talking about) - and there are 36 numbers to choose from (0-35) What is the FORMULA to find out how many possible combinations there are? I know there has got to be a standard formula for this - isn't there? PLEASE Help! Your time & response is greatly appreciated!!

2007-10-22 05:34:48 · 5 answers · asked by Cassie K 2

find dy/dx

x^2+y^2-xy=2

2007-10-22 05:21:29 · 4 answers · asked by tsLow 1

2007-10-22 05:19:46 · 9 answers · asked by Anonymous

If it is true explain why is so, if it is false give a counterexample.

2007-10-22 05:08:01 · 5 answers · asked by gigichic21 1