# Posts by RAchel

Total # Posts: 1,536

**Pre calc**

Sorry steve not everyone is as smart as you. Thanks for your help tho

**Pre calc **

Please help me proof the identity. This isn't even math to me, I can not understand it so please show all work. God bless A)1-cos2x/sin2x=tanx B) sin4x/sinx=4cosxcos2x

**Pre calc**

Thats still the wrong answer

**Pre calc**

The answer I keep getting is -3 square root of 10 over 130

**Pre calc**

sin(? ? ?); tan(?) = 5/12 ? in Quadrant III, sin(?) = ? sqaure root 10/10 ? in Quadrant IV I tried this numerous times can somone please help me

**Chemistry**

Assume you are performing the calibration step and you begin with 70 g of water at 20*C and 70 g of water at 80*C. After adding the two portions of water into your calorimeter setup and following the procedure outlined in the experiment, you determine the temperature of the ...

**precal Please Help**

1-cos (2A)/2sin A+ SIN (2A)= tan (A/2) I need to verify the identity I have no idea how to do that and I have a test please explain!!!

**Calculus**

the problem is asking me to use optimization to find the minimum surface are and then determine how much it would cost to make it

**Calculus**

A manufacturer needs to produce a cylindrical can with a volume (capacity) of 1000cm cubed. The top and the bottom of the container are made of material that costs $0.05 per square cm, while the side of the container is made of material costing $0.03 per square centimeter. ...

**pre calc**

To measure the height of the cloud cover at an airport, a worker shines a spotlight upward at an angle 75° from the horizontal. An observer D = 600 m away measures the angle of elevation to the spot of light to be 45°. Find the height h of the cloud cover. (Round your ...

**A.P Chemistry**

For a certain reaction ?H is 54 kJ/mol and ?S is 128 J/mol · K. This reaction can become spontaneous only above some temperature. What is this temperature? Answer in units of ?C.

**Math**

Find the magnitude and direction angle of p = 42i + 35j

**Math**

Find the exact value of the trig function below. cos a/2 if cosa = - 31/49 (assume cos a/2 is negative)

**civics**

C. Major rule. The people were supposed to be able to have control over the laws that were made and how their country was ruled. Decisions were made based on the majority of opinion.

**math**

I meant to type that it seemed like it would cost at least 1,000

**math**

The annual cost of a gym membership can be represented by the function C(t)=300-5t, where t is the number of years that one has belonged to the gym. If Jeffrey has been a member for 5 years, what is the total amount of money that he has paid to the gym over the past 5 years. I...

**math**

There are 4 romantic novels and 6 adventurous novels on a book shelf. Without looking, Carmen chooses two novels out of the shelf. What is the probability that she chooses 2 romantic novels?

**math**

The probability that Jeff will be accepted to Green Valley College is 3/4, and the probability that Justin will be accepted to Blue Ridge College is 2/5. What is the probability that Justin will be accepted and Jeff will not?

**math**

If 8^x = 12, then 24^x = ? Estimate your answer to one decimal place.

**math**

If 8.2^p = 10.5^q, then p/q = ? Estimate your answer to two decimal places.

**math**

That was my mistake. It was supposed to say k=?

**math**

If 16x^2 - 24x + k = 0 has two roots (a double root) equal to 3/4, 4 = ?

**math**

For his troops' popcorn fundraiser sale, Mike sold caramel corn for $10, buttered microwave popcorn for $8, and lightly buttered popcorn for $7. By the end of the fundraiser, he had sold 400 items and made $3,272. If he sold twice as many lightly buttered microwave popcorn...

**physics**

a force of 372 N is used to move a piano with a maass of 532 kg up a ramp 14 m long. what is the vertical height of the ramp

**math**

If g(x)=x+3 h(x)=9-x^2, what is the maximum of h(g(x))?

**Math**

If cscØ = 4/3, find sinØ + sinØ cot^2 Ø

**Math**

If g(x)=x+3 h(x)=9-x^2, what is the maximum of h(g(x))?

**Calculus**

Find the magnitude and direction angle of p=42i+35j

**Math**

A line has parametric equations x=7t-2 and y=-4+3t. What is the slope of the line representing the direct relationship between x and y?

**Math**

Thanks. All of this was right except it was southwest instead of northeast.

**Trigonometry**

Find the magnitude and direction angle of v = -7i + 3j

**Math**

Thank you

**Math**

Find the components of vector u with a magnitude of 10 and a direction angle of ?=54° Help??

**Math**

1/3 pitcher water + 2 apple juice - 1/3 carton milk =

**write teacher**

Interesting Facts about Frederick Douglass Douglass was married to his first wife Anna for 44 years before she died. They had five children. John Brown tried to get Douglass to participate in the raid on Harpers Ferry, but Douglass thought it was a bad idea. He was once ...

**Math, Quadratic equaitons**

A toy rocket is launched form a 3m platform, at 8.2m/s. The height of the rocket is modelled by the equation h=-4.0t^2+8.1t+3 where h is the height, in metres, above the ground and t is the time, in seconds. After how many seconds will the rocket rise to a height of 6m above ...

**Math**

a recipe for 2 dozen cookies calls for 1 1/3 cups of flour.how much for would be needed to make five dozen cookies?

**Statisics**

The closing price of Schnur Sporting Goods Inc. common stock is uniformly distributed between $23 and $37 per share. What is the probability that the stock price will be: More than $33? Less than or equal to $27?

**Algebra**

Find the next three terms of the Arithmetic sequence, 3/4,1/2,1/4,1,..

**Math**

I have a dash of sugar and I need to add flour with a 1:10 weight ratio of sugar to flour so how much flour do I need

**math**

form a polynomial with a degree of 4 zeros 4,-3i,1 and multiplicity 2

**Physics**

A shopper pushes a cart 50 m south down one aisle and then turns 90.0° west and moves 12 m. He then makes another 90.0° turn and moves 20 m. What is the largest possible displacement of the shopper?

**PRE-CAL**

Factor the trigonometric expression. There is more than one correct form of the answer. cot^2 x + csc x − 19 NOT SURE WHETHER TO REPLACE THE COT WITH COS^2X/SIN^2X THEN CSCX TO 1/SINX?

**Science**

Answer with solution, plz. 1. What is the concentration of the solution by volume when dissolved is used 30 grams & the water is 60 grams. 2. How much solvent in grams is present in a solution with a concentration by volume of 40% the solute of content is 60 grams.

**Math**

Jim has $87. He spends $6 for socks and at least $32 for shoes. How much does he have left to spend on shirts? I know the answer is >49 I need to find the inequality equation. Thank you

**Chemistry**

PLEASE HELP OR I WILL FAIL What would be the final temperature of the system if 16.6 g of lead at 138 ◦C is dropped into 23.4 g of water at 8.68 ◦C in an insulated container? The specific heat of lead is 0.128J/g◦C.

**AP Chemistry**

(DrBob222 please help me) A sample of 1.97 grams of Z is dissolved into 500 grams of water which is in a styrofoam coffee cup. The temperature is monitored and is found to rise from 25.015◦C to 25.484◦C. What is ∆Hsolution for substance Z? Assume no heat is ...

**PRE-CAL**

ok this worked out great! thank you!

**PRE-CAL**

the table is just that r 2% 4% 6% 8% 10% 12% t ? ? ? ? ? ? i will try that out then Thank you

**PRE-CAL**

Complete the table for the time t (in years) necessary for P dollars to triple when interest is compounded continuously at rate r. (Round your answers to two decimal places.) R=2% t=? tried to plug in as A=Pe^rt since continiously 3=e^.02t ? then take the ln of both sides? (...

**PRE-CAL**

Thank you so much!

**PRE-CAL**

Complete the table assuming continuously compounded interest. (Round your answers to two decimal places.) Initial Investment== ? Annual % Rate== ? Time to Double== 11YRS Amount After 10 Years== $1600 Using formula A=Pe^rt ?

**Social Studies**

Another word for lines of latitude is what?

**Social studies**

The degree of latitiude is always listed where It is a cross word

**AP Chemistry**

The reaction of 5.7 grams of fluorine with excess chlorine produced 7.6 grams of ClF3. What percent yield of ClF3 was obtained? Answer in units of %.

**Physics**

a ball is dropped from the top on an 80-m high building. what speed does the ball have in falling 3.5 s? I keep getting the answer 34.3m/s but it is counted wrong. I found an answer on Chegg that say 29.4 m/s but I can't figure out how they are getting that answer.

**AP Psychology**

Jay Weiss, a psychologist, used electric shock on rats in a control group and rats in an experimental group. One group; however, was given a piece of wood to chew on. They had fewer ulcers (open sores or lesions in stomach lining). What is the independent variable and ...

**AP Psychology**

Jay Weiss, a psychologist, used electric shock on rats in a control group and rats in an experimental group. One group; however, was given a piece of wood to chew on. They had fewer ulcers (open sores or lesions in stomach lining). What is the independent variable and ...

**Forensics**

Strontium-90 is a radioactive waste product from nuclear reactors. It has a half life of 29 years. How many years would it take for a quantity of strontium-90 to decay 1/16 of its original mass?

**Math**

Write the greatest odd number that uses the digits 3 4 5 once each

**Nouns**

Sitting Bull's warriors soundly defeated General George A. Custer and his troops at the Battle of the Little Big Horn.

**Math**

70

**Algebra/Quadratic Functions**

The production cost (£C) ofa bicycle in a factory is given by the function C=2x^2-200x+5100, where x is the number of bicycles manufactured per day, find the number of bicycles manufactured per day such that the production cost is a minimum.

**Chemistry**

For the reaction, calculate how many grams of the product form when 3.2 g of CaO completely reacts. Assume that there is more than enough of the other reactant. CaO(s)+CO2(g)→CaCO3(s)

**physics**

a particle executing shm time period t from mean position the time to complete 5/8 oscillation

**Algebra**

With a full tank of gas, if you can drive 465 miles, your car can go 18 miles per gallon. Write an equation to show how many miles (use m for miles) you can drive after using _____ gallons of gas (use g for gallons).

**Algebra**

Geppetto is a puppet maker. He starts the month with 3 puppets ready to sell, and makes 9 puppets per day. Write an equation to model this situation (use d for days and p for puppets).

**Algebra**

After visiting the Titanic, Captain Brain and Mr. Pinky are taking the Alvin submarine back to the surface of the water. They start 1500 meters below the surface of the water, and ascend at 37 meters per hour. Note: under the water is a negative number. Write an equation to ...

**Algebra**

Ricardo visits different states every summer. This summer, he started with 3 states already visited and visits 6 states per day. Write an equation to model this situation (use d for days and s for states).

**Algebra**

Two cyclists, 128 miles apart, start riding toward each other at the same time. One cycles 3 times as fast as the other. If they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

**Algebra**

After robbing a bank in Dodge City, a robber gallops off at 12 mi/h. 30 minutes later, the marshall leaves to pursue the robber at 16 mi/h. How long (in hours) does it take the marshall to catch up to the robber?

**Algebra**

thank you so much

**Algebra**

Valerie needs to rent a car on vacation. The rental company charges $17.95 plus 16 cents for each mile driven. If Valerie only has $50 to spend on the rental, what is the maximum number of miles she can drive?

**Algebra**

Statins are used to keep cholesterol in check and are a top selling drug in the US. The equation S-1.5x=6.4 gives the amount of sales (S) of statin in billions of dollars x years after 1998. According to this equation, how much will/did people spend on statins in the year 2008?

**maths**

Sorry I just typed any number this is my first time using this site....I didn't know that someone would help me with it... thank you

**maths**

11/2

**maths**

A man had16 mangoes.he gave1/4to bob and1/2tohis sister candy.how many mangoes remained after he shared with Bob and Candy?

**Algebra**

A wire 20 cm long is cut into two pieces. The longer piece is 4 cm longer than the shorter piece. Find the length of the shorter piece of wire

**Math**

angle theta is in standard position on a co-ordinate grid. the terminal arm of theta is in quadrent 2 on the line that's equation is 3x-4y=0. Determine the sine of this angle and then the measure of angle theta.

**Math**

During the month of June, Ava kept track of the number of days she saw birds in her garden. She saw birds on 18 days of the month. What experimental probability that she will see birds in her garden on July 1? Can somebody show me how to work this problem out?

**Chemistry**

use the appropriate standard reduction potentials in the appendix of your book to determine the equilibrium constant at 285 K for the following reaction under acidic conditions 4H+(aq) + MnO2(s)+2Fe+2(aq)----> Mn+2 (aq)+2Fe3+(aq)+2H2O(l) The reductions potentials are 1.23 V...

**Chemistry**

In my book it has 1.23 V and 0.770 V for the potentials for the oxidation and reduction equations.But I still can't figure out the answer.

**Geometry**

If you could fold a football field in half, the fifty yard line would the ? Line of symmetry

**Geometry**

Imagine a pie cut into four equal pieces. The angles formed by two adjacent pieces are A) supplementary B) Complementary I choose B is this correct? Imagine a pie cut into eight equal pieces. The angles formed by two adjacent pieces are? Supplementary (A) Am I correct??

**Geometry**

If you could fold a football field in half the fifty yard line would be the ? Find geometry term

**Math**

Thank You Alex!

**Math**

I need help solving the problem below. Chris answered 19 out of 25 questions correctly on a math test. What percent of the questions did she answer correctly? Is the answer 76% 19/25= 0.76

**Physics**

The Equation of Continuity states that the mass flow rate has the same value at every position along a tube that has a single entry and a single exit point for fluid flow. Basically it boils down to the idea that the fluid doesn’t magically disappear or appear. If 2.0 kg ...

**Physics**

Thank you so much!

**Physics**

I know the formula is F=PA but I'm confused on the steps to take. Please help!

**Physics**

A metal block of mass 1.840 kg is hanging from a string. The tension in the string is 9.972 N. The block is submerged in a beaker of fluid and is stationary. What is the magnitude and direction of the buoyant force acting on the block? Consider making a free body diagram ...

**pre algebra**

the length of a rectangle is 6 cm more than its width. if 3 cm are taken from the length and added to the width, the figure becomes a square with an area of 64sq cm. what are the dimensions of the original figure.

**stats**

shipment of 30 computers, 8 are defective. Four computers are chosen at random. Find the probability that: a)Exactly two are defective b)None are defective c)At most two are defective

**Science**

Two pellets, each with a charge of 1.5 microcoulomb (1.5×10−6 C ), are located 2.8 cm (2.8×10−2 m ) apart. Part A Find the electric force between them.Part B What would be the mass of an object that would experience this same force in Earth's ...

**Math troubles**

Where did you get the .25 and .75 from?

**Chemistry**

how much solid KNO3 will crystallize and a saturated solution of KNO3;if the solution is cooled from 65 degrees Celsius to 45 degrees Celsius.

**math**

Find a formula for the inverse of the function. f(n)=4en3. f^[−1](Q)=

**math**

Find a formula for the inverse of the function f(x)=9−4/x2, x>0.

**MATH.**

so what is the answer

**algebra**

How do I write-17-16 as a equivalent addition?