# Posts by lindsay

Total # Posts: 619

**Calculus**

Ohhhh. I see what I did wrong in that second one! Thanks for all your help!(:

**Calculus**

Check my work? The equations given were R(x)=-x^2+400x and C(x)=x^2+40x+100. We were asked to find the maximum profit and minimum average cost. (I'm having trouble remembering how to find a minimum and maximum, so please help with that, if you can!) For Max Profit, I got $...

**Calculus**

I don't remember how to did min/max. I can get as far as the critical numbers...

**Calculus**

How do you find maximum revenue, maximum profit, and minimum average cost? Our teacher gave us a project to teach ourselves the section, but I can't learn very well even with her teaching, so I don't know how I'm supposed to do this...

**Calculus**

That helped a whole lot! Thank you so much!

**Calculus**

Find limit as x->-3 of (sin(4x+12))/(5x+15)

**Math**

Let f(x)= lim as h->0 of ((x+h)^2-x^2)/ h. For what value of x does f(x)= 4?

**Calculus Please Help!!**

Thanks! When it asks to find the rate the area is changing at that point in time, did you get the answer -357/5? Because I did, but it doesn't seem right...

**Calculus Please Help!!**

"A 13-foot ladder is leaning against a building when its base begins to slide away from the base of the building. By the time the base is 12 feet from the building, the base is moving at the rate of 6 ft/sec. How fast is the top of the ladder sliding down the wall at that...

**CALCULUS HELP!!**

I haven't done this type of problem in a while, so if someone can just show me how to set it up, I can figure out the rest. (: "A 13-foot ladder is leaning against a building when its base begins to slide away from the base of the building. By the time the base is 12 ...

**Chemistry**

How much energy would be needed to turn 183.7 g of Ice at -27 degrees celcius to steam at 135 degrees celcius?

**BIO**

Explain why routine blood measurement of glycated hemoglobin is used to determine whether a diabetic has good glucose control.

**Calculus**

Determine if Rolle's Theorem can be applied. If it can, find all values of c such that f'(c)=0. f(x)=x^3-9x, [-3,3]

**Creative Writing**

Need help describing something. I'm not good at writing horror or graphic death and such. In my story, a tree's branches basically 'come to life,' but I'm not sure what kind of details to use for the branches if they're like elastic and bend and twist ...

**Journalism**

Hmmm....That one would be okay, I suppose. Might attract more people. Thanks!

**Journalism**

Heh...I'm a fiction writer, not a journalist, so it's really hard for me ... The article isn't finished yet - it's barely even started. And it's still kind of choppy because I haven't really done much editing and reordering and stuff just yet. [There ...

**Journalism**

Maybe I could just start with a question?

**Journalism**

I tried writing the opening to my article on vegetarianism and this is what I got so far. [A lot of people like to sit down at night and eat a big, juicy steak – and then there are those who prefer an organic meal without any meat. Vegetarianism is not uncommon, but it&#...

**Journalism**

I've started working on an article for my Journalism class about vegetarianism - pros and cons, and why or why not people at my school support it. I've gotten a few paragraphs in, but I'm having trouble on writing the lead. Any suggestions?

**Phyics**

to find the distance multiply radius*2 and then take that answer and multiply it by pi (3.14) to get the total distance around lake then multiply the total by 0.75 to get answer for the distance traveled

**Physics**

A bowling ball traveling with constant speed hits the pins at the end of a bowling lane 16.5 m long. The bowler hears the sound of the ball hitting the pins 2.51s after the ball is released from his hands. What is the speed of the ball? The speed of sound is 340 m/s

**Physics**

A stone is thrown vertically upward with a speed of 19.0m/s How fast is it moving when it reaches a height of 10.0m

**Math**

Describe the intervals on which the following function is continuous. If not continuous, state "where" the discontinuity occurs and state the TYPE of discontinuity. f(x)= (x^2-x-12)/(x^2-6x+8) I just don't understand how to find the intervals. Thanks~

**math**

Find the exact value of 1. tan 75 degrees 2. Cos 15 degrees 3. Sin 105 degrees

**math**

Two pieces of wire are stretched from the top M, of a vertical pole to the points L and N on the horizontal ground, The angle of depression of L from M is 65 degrees. N is on the opposite side of the pole (from L) at an angle of depression of 72 degrees from M. N is 4m from ...

**math**

Dave walked from point A to point B due North East for a distance of 20m. He immediately changed direction and walked 50m from B to C on a bearing of 110 degrees. i. Calculate the distance AC ii. Find the bearing of C from A

**math**

Dave walked from point A to point B due North East for a distance of 20m. He immediately changed direction and walked 50m from B to C on a bearing of 110 degrees. i. Calculate the distance AC ii. Find the bearing of C from A

**math**

Prove that Sin x + tan x / 1+cosx =tan x

**math**

If the bearing fron H to G is 098 degrees, what is the bearing of G from H

**math**

Solve the equation 8 cos^2 X -2 =0 given that 180< or equal to X <or equal to 360 degrees.

**math**

Triangle DEF is such that DF=8cm,EF=5.5cm and its area is 11 root2 cm^2. Find angle EFD.

**math**

Given the function y= 4cos(2x+90degrees)-3, Find the value of y when x =30 degrees.

**math**

Simplify cos Theta/4 cos theta/4 - sin theta/4 sin theta/4.

**math**

Triangle XYZ with vertices X(3,-1) Y(7,-3)Z(3,-5) undergoes an enlargement represented by the mapping: (x)--(-0.5 0)(x) +(-3) (y)--( 0 -0.5)(y) +(4) Evaluate: 1. The vertices of the image of triangle XYZ. 2. The centre of enlargement PS. The small brackets should be one big ...

**math**

Triangle XYZ with vertices X(3,-1) Y(7,-3)Z(3,-5) undergoes an enlargement represented by the mapping: x

**math**

Three students, Chris, Vlad, and Steve, are registered for the same class and attend independently of each other. If Chris is in class 80% of the time, Vlad is in class 85% of the time, and Steve is in class 90% of the time, what is the probability that at least two of them ...

**4th grade math**

i don't think it is right but 72

**math**

The 9th term of an AP is 8 and the 4th term is 20. Find the first term and the common difference.

**math**

find the exact value of [sec(-30 degrees)- cot 120 degrees]/1-cosec^2(45 degrees) Find the exact value of [sin^2(355 degrees) + cos^2 (355 degrees)]/ tan^2 (30 degrees)

**math**

This is a matrix question. R is the matrix (3r 1) (s 2s) 1. State, in terms of s and r the determinant of R 2. If r=1/3 and s=4 determine the inverse of R 3.State the pair of r and s not including 0, which would make the matrix R a singular matrix

**math**

This is a matrix question. R is the matrix (3r 1) (s 2s) 1. State, in terms of s and r the determinant of R 2. If r=1/3 and s=4 determine the inverse of R 3.State the pair of r and s not including 0, which would make the matrix R a singular matrix

**math**

This is a matrix question but I can't get a single bracket so I will use two. (a b)(5 1) =(12 -2) (3 0)(-2 4) (15 3) Find the values of a and b.

**math**

A sequence is generated by the recurrence relation Ur+1 = 1/Ur -3. Given that U2 = U1 find the possible of U1

**math**

a species of orchid is being studied. The population 'p' at time 't' years after the study started is assumed to be p = 2800ae^0.2t/1 + ae^0.2t where 'a' is a constant. Given tnat there were 300 orchids when the study started. a. show that a =0.12 b. ...

**trigonometry**

A sector AOB of a circle, centre O, radius r cm, where the acute angle AOB is theta radians. Given that the perimeter of the sector is 14 cm and that the area of the sector is 10 cm^2, evaluate r and theta.

**Economics**

We're looking at the market for cat food. When the price is $10, the quantity sold is 1000 bags. When the price drops 10%, the quantity sold increases 30%. Calculate the price elasticity of demand. (Answer in format X.XX, round to the nearest hundredth.) I know the formula...

**math**

Can you explain how I find the values so I can plot a graph of T=(25 ln24/ln) -(25/ln2) ln M

**SOC203**

Not the answer it gave on weegy!!

**math 11**

Current price is $100, current salesbare 5000 units. For every increase in price of $1, sales decrease by 20 units. Find optimum revenue.

**algerbra 2**

3. Write the function R that models the total number of components that reenter the atmosphere around the earth each year.

**math**

Calculat the absolute value of: 4-{x-3}=0 PS. The brackets are supposed to be the straight lines for the absolute symbols.

**math**

Hi Reiny, I did not get any parentheses with the question. I got it the way I typed it. Thanks.

**math**

If f(x)=2x+1/x-3 and g(x)=1-x/2 Show that f(g)(x)=g(f)(x)

**math**

Given that h(x)=x+1/x-2 and g(x) =4-x. Find h(g)(x) and find g(h)(x). P.S. Thanks for the correction Steve.

**math**

Given that h(x) =x+1/x-2 and g(x)=4-x. Find hg(x) and find gh(x)

**math**

Find the range of values of 'c' for which g(x)= -3x^2-4x-c has complex roots

**math**

The function f:x =2x+1/x-3 and g:x =1-x/2 a. For what value of x is 'f' undefined? b. Find 'f' inverse and hence solve f(x) =1/3. c.Show that fg(x) -gh(x).

**math**

I need to sketch the graph of t(x)=2x^2 +3x > or equal to 10x-x^2. How do I work out the points to plot on the graph?

**math**

Write 2x^2+6x-5 in the form of a(x+h)^2 +k where a,h,k, are real numbers.(using completing the squares)

**math**

A motorist travelling at a steady speed of 120km/h covers a section of the highway in 30min. After a speed limit is imposed he finds that when travelling at the maximum speed allowed he takes 20 min. longer than before to cover the same section. Calculate the speed limit.

**math**

A rectangular pool's depth is 1m at the shallow end and gradually increases to 4m at the deep end. The pool is 32m in length and 12m width. 1. calculate the total surface area (m squared) of the pool. 2. The cost of painting the pool at $5 per square foot. 3. the amount of...

**math**

Sorry, the diameter of 20cm and height of 8cm is for the cylinder.

**math**

A paperweight containing liquid is made up of a cone and a cylinder. The radius of the cone is 3cm with height of 4cm. The diameter is 20cm and height is 8cm. 1. Calculate the total volume of the cone and cylinder when it si empty, leaving your answer in terms of pi. 2. If the...

**math**

A fish tank is 50 cm long, 34 cm wide and 24 cm high. It contains water to depth of 18 cm. Four identical spheres are placed in the tank and are fully submerged. The water level rises by 4.5 cm. 1.What is the volume before the spheres were added? 2. What is the volume of each ...

**Math**

A recipe for cake calls for 5 and 1/4 cup of flour. The chef mistakenly adds 7 and 2/3 cups of flour to the mixture. How much flour does the chef need to remove from the mixture?

**math**

Can 0/3 + 3 be simplified? Can 10m + 1 / 10 be simplified?

**math**

Maria ran 3 and 4/5 miles. She ran 1 and 2/3 miles further than Paul. Write the equation.

**math**

a cyclist travels the 30 km from Town A to Town B at an average speed of 25 km/h and immediately continues the journey to town C, which is a further 60 km away at an average speed of 20 km/h. What is the average speed for the whole journey?

**math**

1.John deposited $40,000.oo in the bank and earned simple interest of 7% per annum for 2 years. calculate the amount he will receive at the end of the 2 year period. 2. Find the simple interest on $15,000.00 invested for 4 years at 12% per annum.

**math**

An article can be bought for cash at $20,000.00. A customer bought it on hire purchase by paying a deposit of 20%. An interest of 10% was charged on the remaining balance and he was required to pay the balance in 15 monthly installments. 1.What is the interest charged? 2.The ...

**math**

Consider the relation R = (a,b),(a,c),(c,c),(b,b),(c,b),(b,c) on the set A = a,b. Is R reflexive? Symmetric? Transitive? and why or why not.

**Physics**

what else elena...???

**geology**

Granite 585 Gabbro 1843 Gneiss 3660

**physics**

A 58.4-kg person, running horizontally with a velocity of +3.84 m/s, jumps onto a 10.7-kg sled that is initially at rest. (a) Ignoring the effects of friction during the collision, find the velocity of the sled and person as they move away. (Indicate the direction with the ...

**Physics**

A jet is circling an airport control tower at a distance of 23.0 km. An observer in the tower watches the jet cross in front of the moon. As seen from the tower, the moon subtends an angle of 9.49 10-3 radians. Find the distance traveled (in meters) by the jet as the observer ...

**Geology**

Granite 585 Gabbro 1843 Gneiss 3660

**math**

How to solve 13 is 10 percent of what number?

**Physics**

An artillery shell is fired with an initial velocity of 300m/s at 55.0 degrees above the horizontal. To clear an avalanche, it explodes on a mountainside 42.0s later. What are the x and y coordinates of the shell where it explodes, relative to its firing point? a) (1.68km, 7....

**Physics. Really stuck!**

two blocks of masses m1 and m2 (m1>m2) are placed on a frictionless table in contact with each other. A horizontal force of magnitude F is applied to the block of mass m1. if P is the magnitude of the contact force between the blocks, what are the net forces acting on m1 ...

**chemistry**

How many photons are produced in a laser pulse of 0.324 J at 631 nm?

**chemistry**

To resolve an object in an electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic energy must the electrons have in order to resolve a protein molecule that is 8.10 nm in diameter? Take the mass of an electron to be 9.11&...

**English**

List the compound nouns in this sentence. Philo T. Farnsworth was the first American inventor to use television technology. The answers were Philo T Farnsworth, American inventor, and television technology. Can a proper noun also be a compound noun?

**PHYSICS**

A car is safely negotiating an unbanked circular turn at a speed of 29 m/s. The road is dry, and the maximum static frictional force acts on the tires. Suddenly a long wet patch in the road decreases the maximum static frictional force to one-ninth of its dry-road value. If ...

**Math. Due in 4 hours. Please helpp!**

A female moth lays nearly 150 eggs. In on year there may live up to five generations. Each larva eats about 20mg of wool. Assume that 2/3 of the eggs die and that 50% of the remaining moths are females. Estimate the amount of wool that may be destroyed b the descendants of one...

**i don't get it**

thanks

**i don't get it**

why does everybody not like a teacher's pet?

**math**

What ia A inverse if A = (3 -2) (3 2)

**math**

Solve the inequality 2x^2<12-5x

**math**

Solve the equation 3^2x - 12 x 3^x + 27 = 0

**math**

simplify the following giving your answer with a rational denominator, 2 root3 - root 3/ 2 + root three.

**Trigonometry**

1. ((cosx)/(1 + sinx))+((1 + sinx)/(cosx)) 2. ((cos(x)cot(x))/(1 - sin(x)))-1

**math**

solve: n squared + 5n = 84 for n?

**physics**

to start a nuclear fusion reaction, two hydrogen atoms of charge 1.602x10^-19 and mass 1.67x10^-27kg must be fired at each other. If each particle has an initial velocity of 2.7x10^6m/s when released, what is their minimum seperation?

**physics**

a square with side length 2.0 cm has a charge of -1.0x10^-6C at every corner. What is the magnitude and direction of the electric force on each charge? What is the force on a fifth charge placed in the centre of this square? Does the sign of the fifth charge affect the ...

**physics**

a metal ball with a charge of 5.4x10^8 electrons is touched to another metal ball so that all the excess electrons are shared equally. What is the final cahrge on the first ball?

**Math**

g(x)= -3x^2 g(f(x))= -3(x^2-4)^2 -6(x^2-4)(2x) -6x^2-24 (2x) -12x^3-48x -12x(x^2+4) f(g(x))= (-3x^2)^2-4 2(-3x^2)(-6x)-4 -6x^2(-6x)-4 36x^3-4 4(9x^3-1)

**geometry**

Given that P=(2,10) (5,-3) a. Evaluate the inverse P^-1, of P b. use a matrix method to solve x(2,5)+ y(1,-3) =(7,1)

**geometry**

The towns A and B are on the circle of latitude 24 degrees N.The longitude of A is 108degrees E and longitude B is 75 degrees E. a. Calculate the radius of the circle of latitude 24 degrees N. b.The shortest distance between A and B measured along the circle of latitude 24 ...

**geometry**

The points A=(1,1) B=(3,4) connects to point C (3,1). a. Find the length of AB b. The gradient and equation of line AB

**geometry**

R =(cos0 -sin0) (sin0 -cos0) State the matrix R for 0=120 degrees NB 0 represents theta