# pre calculus

Most popular questions-
## Pre Calculus

Find all $2 \times 2$ matrices $\bold{A}$ that have the property that for any $2 \times 2$ matrix $\bold{B}$, \[\bold{A} \bold{B} = \bold{B} \bold{A}.\]

*asked by Bob on September 20, 2017* -
## pre calculus

A taxi company charges $2.00 for the first mile (or part of a mile) and 20 cents for each succeeding tenth of a mile (or part). Express the cost C (in dollars) of a ride as a piecewise-defined function of the distance x traveled (in miles) for 0

*asked by Danielle on March 27, 2014* -
## Pre Calculus

Identify the parametric equations that represent the same path as the following parametric equations. x(t)=2cos2t y(t)=sin3t a. x(t)=2cos2t y(t)=sin6t b. x(t)=4cos4t y(t)=sin6t c. x(t)=2cos4t y(t)=sin6t d. x(t)=4cos2t y(t)=2sin3t

*asked by line on May 18, 2018* -
## pre calculus

cube roots of 64i?

*asked by joe on May 20, 2011* -
## Pre Calculus

Find the number of units that produces maximum revenue given by R = 900x-0.1x^2, where R is the total revenue in dollars and x is the number of units sold.

*asked by Amy on October 3, 2018* -
## Pre Calculus

The third term of a geometric series is 24 and the fourth term is 36. Determine the sum of the first 10 terms. Express your answers as an exact fraction.

*asked by HanuMath25/11 on November 25, 2012* -
## Pre Calculus

Two forces with magnitudes of 150 and 75 pounds act on an object at angles of 30° and 150°, respectively. Find the direction and magnitude of the resultant force. Round to two decimal places in all intermediate steps and in your final answer. Having lots

*asked by maria on August 18, 2016* -
## pre calculus

the downhill ski club is organizing a ski trip. group tickets for the ski trip are priced at 20 for the first 100 skiers and a discount of 5.00 for each of the skiers over 100. a) write a formula to find the average cost of x skiers. b)write a formula to

*asked by syed on April 3, 2015* -
## Pre Calculus

Radium-221 has a half-life of 30 s. How long will it take for 95% of a sample to decay

*asked by Shellie on July 26, 2009* -
## pre calculus

A parallelogram has a 70 degree angle and sides 6 cm and 10 cm long. How long are its diagonals?

*asked by lelelelel on December 1, 2010* -
## pre calculus

A force of 350 lb. is resolved into forces at right angles to one another, the angle of F2 being 67 from the 350 lb. force. Find F2.

*asked by jacob on January 2, 2019* -
## pre calculus

Cot 495 degrees... a) -tan 135 degrees b) -cot 135 degrees c) cot 135 degrees d) -cot 315 degrees

*asked by Anonymous on May 13, 2013* -
## pre calculus

For a given right triangle, side a = 400 feet and side b = 900 feet. What is the measure of angle B to the nearest degree?

*asked by Kelsey on November 30, 2012* -
## pre calculus

Forces with magnitudes of 250 pounds and 130pounds act on an object at angles 45degrees and -60degrees respectively with the positive axis. Find the direction and magnitude of the resultant of these forces.

*asked by Anonymous on November 26, 2016* -
## pre calculus

Jack invests $1000 at a certain annual interest rate, and he invests another $2000 at an annual rate that is one-half percent higher. If he receives a total of $190 interest in 1 year, at what rate is the $1000 invested?

*asked by Danielle on March 4, 2014* -
## Pre Calculus

Prove that 2/square root 3cosx-sinx=sec(pi/6-x)

*asked by Nathan on April 22, 2010* -
## pre calculus

A ship’s sonar detects a submarine 880 feet below a point on the ocean’s surface 1450 ft dead ahead of the ship. To the nearest degree, find the angle x.

*asked by devante on September 14, 2015* -
## pre calculus

A velocity of 30 mph is resolved into two components, each of which makes an angle of 45 degrees with it. Find their magnitude.

*asked by danders on March 18, 2010* -
## Pre Calculus

Find the exact value ofcos (u+v) given that sin u= 7/25 and cos v=−12/13. (Both u and v are in Quadrant II.)

*asked by Jessica Maths on July 11, 2016* -
## Pre Calculus

For a given right triangle, side a = 76.4 feet and side b = 39.3 feet. What is the measure of angle A to the nearest degree?

*asked by Kelsey on November 30, 2012* -
## Pre calculus

A plane is headed due south with an airspeed of 190 mph. A wind from the direction of S 40 degrees W is blowing at 30 mph. Find the groundspeed of the plane, rounded to the nearest whole number

*asked by Jacob on October 30, 2015* -
## Pre Calculus

(a) Determine the number of terms, n, if 3+3^2+3^3+..........+3^n= 9840. (b) Three numbers, a, b and c form a geometric series so that a+b+c = 35 and abc = 1000. What are the values of a, b and c ?

*asked by HanuMath25/11 on November 25, 2012* -
## Pre Calculus

The population P of a culture of bacteria is described by the equation P = 1600e^0.052t where t is time, in hours, relative to the time at which the population was 1600. (a) What was the population at t = 6 hours? Show your work. (b) After how many hours

*asked by Jessica Maths on July 6, 2016* -
## pre calculus

Choose the point on the terminal side of 135°

*asked by Anonymous on June 1, 2013* -
## pre calculus

For a given right triangle, angle A = 61± and side b = 39 feet. What is the length of side a to the nearest foot?

*asked by Kelsey on November 30, 2012* -
## Pre Calculus

Evaluate log b {square root of 10b}, given that log b 2 = 0.3562 and log b 5 = 0.8271 (sorry I had no clue how to type this in math format!)

*asked by Shellie on July 26, 2009* -
## pre calculus

You set up a business and make an initial investment of $10,000. The unit cost of the product is $2.85 and the selling price is $4.95. How many units must you sell to break even?

*asked by nichole on January 7, 2009* -
## pre calculus

For a given right triangle, side a = 76.4 feet and side b = 39.3 feet. What is the length of side c to the nearest tenth of a foot?

*asked by Kelsey on November 30, 2012* -
## pre calculus

The conic section whose equation is x 2 - 3y 2 - 8x + 12y + 16 = 0, is in Position is I. Is this true or false?

*asked by aaa on March 29, 2010* -
## Pre Calculus

Find the magnitude and direction angle for the vector v=3 cos 123 degrees i + 3 sin 123 degrees j.

*asked by ADOG on May 17, 2018* -
## Pre Calculus

For a vector $\bold{v}$, let $\bold{r}$ be the reflection of $\bold{v}$ over the line \[\bold{x} = t \begin{pmatrix} 2 \\ -1 \end{pmatrix}.\] [asy] unitsize(1 cm); pair O, V, R; O = (0,0); V = (3,1); R = reflect(O,(2,-1))*(V); xaxis(-2,4); yaxis(-3,1);

*asked by Bob on September 20, 2017* -
## Pre Calculus

(cotx)(cscx)+secx=(csc^2x)(secx) Please help to verify this trigonometric identity.

*asked by Marie on November 4, 2012* -
## pre calculus

You are building a (rectangular) pool in your backyard. It measures 30m in the north-south direction and 25 meters east-west. (Some pool!) The bottom of the pool is a slanted plane so that it's 1m deep along the southern edge and 10m deep along the

*asked by Dunni on January 21, 2016* -
## Pre Calculus

If you are riding on a Ferris wheel that is 60 feet tall and it takes 5 minutes to make a one revolution, what is your linear velocity? A. 0.62 feet per second B. 0.31 feet per second C. 37.68 feet per second D. 3.14 feet per second E. 9.42 feet per second

*asked by Deontre on April 22, 2013* -
## pre calculus

9x^2 + 16y^2 - 36x + 96y + 36 = 0 How do i find the major axis?

*asked by mike on March 26, 2010* -
## pre calculus

Find all of the solutions of the equation x4-625i=0 and represent the solutions graphically. what is the next step to answer the question? (x^2-25√i)(x^2+25√i) (x-5∜i)(x+5∜i)(x-5∜i i)(x+5∜i i) i = 1 cis π/2 ∜i = ∜1 cis π/8

*asked by Anonymous on November 27, 2016* -
## pre calculus

The diameter of the wheels on your car (including the tires) is 25 inches. You are going to drive 218 miles today. Each of your wheels is going to turn by an angle of how many degrees? Hint: A mile has 5280 feet, a foot has 12 inches, and the circumference

*asked by Dunni on January 21, 2016* -
## PRE CALCULUS

8-12SIN^2X=4COS^2X SOLVE FOR X

*asked by NN on December 12, 2011* -
## Pre calculus

When “superballs” sprang upon the scene in the 1960’s, kids across the United States were amazed that these hard rubber balls could bounce to 90% of the height from which they were dropped. If a superball is dropped from a height of 2 m, how far does

*asked by Clark on April 24, 2017* -
## Pre Calculus

Evaluate the function f(x) = log3 x at x =1/27 without using a calculator a. –4 b. –2 c. 1/27 d. –3 e. 27

*asked by Jessica Maths on July 5, 2016* -
## Pre Calculus

Exponential growth and decay find the half life of a radioactive substance if 220 grams of the substance decays to 200 grams in 4 years?

*asked by Josh on October 25, 2011* -
## Pre Calculus

Tritium, a radioactive isotope of hydrogen, has a half-life of 12.4 years. Of an initial sample of 69 grams, how much will remain after 75 years? a. 1.5848 grams b. 61.5289 grams c. 0.0000 grams d. 1.0426 grams e. 17.2500 grams

*asked by Jessica Maths on July 6, 2016* -
## pre calculus

For a given right triangle, side a = 490 feet and side b = 960 feet. What is the measure of angle B to the nearest degree?

*asked by Kelsey on November 30, 2012* -
## Pre Calculus

Let $\bold{w} = \begin{pmatrix} 2 \\ -1 \end{pmatrix}$. There exists a $2 \times 2$ matrix $\bold{P}$ such that \[\text{proj}_{\bold{w}} \bold{v} = \bold{P} \bold{v}\] for all 2-dimensional vectors $\bold{v}$. Find $\bold{P}$.

*asked by Bob on September 20, 2017* -
## pre calculus

A projectile is fired straight upward from ground level with an initial velocity of 320 feet per second. (Assume t = 0 seconds corresponds to the time the object is fired. Use 32 feet/second2 as acceleration due to gravity.) (a) At what instant will it be

*asked by Shaunna on February 27, 2017* -
## Pre Calculus

A park has a circular walking path with a diameter of 250 meters. a) Write the equation to describe the walking path in your diagram. b) Find the distance traveled by someone walking once around the entire path. c) Find the distance traveled by someone

*asked by Erika G. on October 18, 2015* -
## Pre Calculus

Pre Calculus why is sin(-20)/cos 380 equal to tan (-200)

*asked by Pre Calculus on November 15, 2009* -
## Pre Calculus

A contractor is to fence off a rectangular field along a straight river, the side along the river requiring no fence. What is the least amount of fencing needed to fence of 30,000 meters squared?

*asked by Lauren on March 4, 2013* -
## Pre Calculus

Approximate, to the nearest 0.01 radian, all angles theta in the interval [0,2pi) that satisfy the equation. a.) sin theta=-0.0135 b.) cot theta=-2.731 Thank you for helping! I appreciate it!

*asked by Anonymous on January 24, 2015* -
## pre calculus

1.) If h(x)= (fog)(x) and h(x) = 3 over the square root of x+3 , find g(x) if f(x)= 3 over the square root of x+2. my answer is x+1. Am I right? 2.)If f(x)=3x,g(x)=x-3,and h(x)= the square root of x, find (fogox)(X). I really didn't get this will someone

*asked by Leo on April 6, 2013* -
## Pre Calculus

A cylinder shaped can needs to be constructed to hold 200 cubic centimeters of soup. The material for the sides of the can costs 0.02 cents per square centimeter. The material for the top and bottom of the can need to be thicker, and costs 0.06 cents per

*asked by Joey on April 29, 2016* -
## Pre Calculus

At a glassware factory, molten cobalt glass is poured into molds to make paperweights. Each mold is a rectanglar prism whose height is 3 inches greater than the length of each side of the square base. A machine pours 20 cubic inches of liquid glass into

*asked by Nadia on January 18, 2015* -
## pre calculus

sinB + cosB cotB = cscB

*asked by Orlando on October 9, 2014* -
## pre calculus

Write the complex number z=-2+2i in trigonometric form.

*asked by Anonymous on November 26, 2016* -
## Pre calculus

at an archaeological site remains of plant material will found to have 28.9% of the amount of carbon-14 in a living sample. What was the approximate age of the plant material?

*asked by crisly on December 6, 2014* -
## Pre calculus

Your computer supply store sells two types of laser printers. The first type, A, has a cost of $86 and you make a $45 profit on each one. The second type, B, has a cost of $130 and you make a $35 profit on each one. You expect to sell at least 100 laser

*asked by Maddie on March 4, 2016* -
## pre calculus

The base of an Isosceles triangle is half as long as the two equal sides. Write the area of the triangle as a function of the length of the base. the answer is: A=a^2times the square root of 15 ------------------------------ 4 How did they get this answer?

*asked by Acorn on September 1, 2008* -
## Pre Calculus

A 40-foot flagpole casts a 30-foot shadow. How do you Find o, the angle of elevation?

*asked by Irene on February 25, 2019* -
## pre calculus

Describe the advantages and disadvantages of The method of substitution”, “The method of graphing”, and “The method of elimination” of solving systems of equations

*asked by Anonymous on November 29, 2016* -
## pre calculus

Use Hooke's Law for springs, which states that the distance a spring is stretched (or compressed) varies directly as the force on the spring. A force of 265 newtons stretches a spring 0.15 meter. (a) What force is required to stretch the spring 0.2 meter?

*asked by tanner on October 2, 2014* -
## Pre Calculus

The burial cloth of an Egyptian mummy is estimated to contain 56% of the carbon-14 it contained originally. How long ago was the mummy buried? (the half-life of carbon-14 is 5730). Please round the answer to the nearest tenth. I have figured that: m(t) =

*asked by Shellie on July 24, 2009* -
## pre calculus

The perimeter of a rectangle is 480 meters and its length is 1.5 times its width. find the dimensions of the rectangle.

*asked by nichole on January 7, 2009* -
## pre calculus

find rate of change for p^4-3p^3+500

*asked by CJ on November 4, 2018* -
## Pre Calculus

Find the value of x. log4 65,536 = x a. x = 32,768 b. x=8 c. x = 65,536 d. x=4

*asked by Jessica Maths on July 6, 2016* -
## Pre Calculus

The doubling period of a baterial population is 10 minutes. At time t=80 minutes, the baterial population was 50000 1What was the initial population at time t=0 2Find the size of the baterial population after 4 hours

*asked by Marina on September 24, 2015* -
## pre calculus

the downhill ski club is organizing a ski trip. group tickets for the ski trip are priced at 20 for the first 100 skiers and a discount of 5.00 for each of the skiers over 100. a) write a formula to find the average cost of x skiers. b)write a formula to

*asked by syed on April 3, 2015* -
## Pre Calculus

I keep trying to solve this by factring but I can't seem to get! It's so frustrating! The problem is 1+tan2x=0 This is how I worked the problem before: 1+((2tanx)/(1-tan^2x))=0 ((2tanx)/(1-tan^2x))= -1 Then I cross multiplied to get: -1 + tan^2x = 2 tanx

*asked by Jen on April 11, 2013* -
## pre calculus

For a given right triangle, angle A = 61± and side b = 39 feet. What is the length of side c to the nearest foot?

*asked by Kelsey on November 30, 2012* -
## Pre Calculus

Exponential Growth and Decay Find the half-life of a radioactive substance that decays by 5% in 9 years.

*asked by Josh on October 22, 2011* -
## pre calculus

The conic section whose equation is x^2 - 3y^2 - 8x + 12y + 16 = 0, is in Position is I. Is this statement true or false

*asked by aaa on March 29, 2010* -
## pre calculus

The population of foxes in a certain region over a 2-year period is estimated to be P1(t) = 300 + 50 sin(πt/12) in month t, and the population of rabbits in the same region in month t is given by P2(t) = 4000 + 400 cos(πt/12) . Find the rate of change of

*asked by ChrismB please help me on May 12, 2016* -
## Pre Calculus

Let θ be an angle in quadrant IV such that cosθ = 4/9. Find the exact values of csc θ and cot θ. I am just completely lost! Thanks!

*asked by Anonymous on June 26, 2015* -
## Pre Calculus

The logistic growth function P(t)= 160/ 1 + 9e^-0.165t describes the population of the endangered species of elk "t" years after they were introduced into the habitat. a. How many elk were initially introduced into the habitat? b. How many elk are expected

*asked by Brianna on November 20, 2014* -
## pre calculus

Environmental Concerns: The spread of oil leaking from a tanker is in the shape of a circle. If the radius r (in feet) of the spread after t hours is r(t) = 200sqrt t, find the area A of the oil slick as a function of the time t. I don't get this at all.

*asked by Matt on April 24, 2013* -
## pre calculus

A state makes auto license plates that have two letters (excluding I, 0, and Q) followed by four digits of which the first digit is not zero. How many different license plates are possible?

*asked by ron on March 30, 2010* -
## Pre Calculus

Determine the quadrant in which an angle, θ, lies if θ = 5.40 radians. a. 4th quadrant b. 3rd quadrant c. 2nd quadrant d. 1st quadrant

*asked by Jessica Maths on July 10, 2016* -
## Pre Calculus

Assume that x, y, and b are positive numbers. Use the properties of logarithms to write the expression logb ^8xy in terms of the logarithms of x and y. a. logb^8 + logb x + logb^y b. logb^8+logbx c. logb^8+logby d. logb^8 + log8 x + log8^y e. logb^8+log8xy

*asked by Jessica Maths on July 6, 2016* -
## pre calculus

The age of a document is in dispute, so archaeologists test for carbon-14. Due to radioactive decay, the amount A of carbon -14 present compared to the initial amount A0 after t years is given by the formula A(t) = A0e^-0.000124t . If 72% of the original

*asked by Raju on February 8, 2014* -
## Pre Calculus

A bank teller is counting the total amount of money in a cash register at the end of the day. There is a total of $2600 in denominations of $1, $5, $10 and $20 dollar bills. The total number of paper bills is $235. The number of twenty dollar bills is

*asked by Jona on February 19, 2013* -
## pre calculus

For a given right triangle, side a = 76.4 feet and side b = 39.3 feet. What is the length of side c to the nearest tenth of a foot?

*asked by Kelsey on November 30, 2012* -
## pre calculus

A farmer will be adding a rectangular corral to his barn. He has 600 feet of fencing. The part of the barn that is attached to the corral is 150 feet long. Write a function for the area of the corral, A(x) and include the domain Find the answers for both

*asked by stephenie on October 9, 2012* -
## pre calculus

9x^2 + 16y^2 - 36x + 96y + 36 = 0 how do i find the domain to this problem?

*asked by ppp on March 26, 2010* -
## Pre calculus

in the equation r= 5/(sin theta +2cos theta) the letters r and theta represent polar coordinates. Write the equivalent equation using rectangular coordinates. Thanks :)

*asked by Meredith on December 19, 2016* -
## Pre Calculus

A flare is launched straight up with a velocity of 200 feet per second. The function h(t)= 200t−16t^2 models the height h(t)of the flare are at time t. How many seconds will it take for the flare to hit the ground?

*asked by Michelle on December 5, 2016* -
## Pre Calculus

The revenue and cost equations for a product are R=x (50-0.002x) and C= 12x+ 150000. Where R and C are measured in dollars and x represents the number of units sold. How many units must be sold to get a profit of at least 1,650,000

*asked by Destiney on March 26, 2016* -
## Pre Calculus

A motorboat travels 48 miles down a river in the same time it takes to travel 32 miles up the river. If the rate of the current is 4 miles per hour that is the rate of the boat still water?

*asked by Jody on September 15, 2014* -
## Pre calculus

Tanx + sinxsecx/ cscxtanx

*asked by Kristen on February 10, 2013* -
## pre calculus

A wire 10m long is cut into 2 pieces. one piece will be cut into a square the other piece will be shaped into a circle. Graph A= A(x) for what value of x is A smallest?

*asked by ann9012 on November 18, 2012* -
## pre calculus

A small fast food restaurant invests $4000 to produce a new food item that will sell for $3.50. Each item can be produced for $2.15. How many items must be sold in order to break even? Round to the nearest item.

*asked by Anonymous on November 28, 2016* -
## pre calculus

A triangular parcel of land has borders of lengths 55 meters, 85 meters, and 100 meters. Find the area of the parcel of land.

*asked by Anonymous on November 26, 2016* -
## Pre Calculus

The following table shows the rate of water flow (in L/min) through a dam. t (min) 1 5 9 13 17 21 25 V'(t) (L/min) 6 6 2 2 3 6 2 Approximate the total volume of water that passed through the dam from t=1 to t=25 using Simpson's rule, with n=6.

*asked by John on May 12, 2016* -
## Pre Calculus

(secx)/(tanx)+(cscx)/(cotx)=secx+cscx Please help me verify this trigonometric identity.

*asked by Lainey on November 1, 2012* -
## Pre Calculus

Exponential and log functions What initial investment at 8.5% compounded continuously for 7 years will accumulate to 50,000?

*asked by Josh on October 23, 2011* -
## Pre Calculus

use a calculator to find approximate solutions of the equation. 8.06x^2+25.8726x-25.047256=0

*asked by Carol on September 27, 2009* -
## Pre Calculus

A piece of cardboard measuring 13 inches by 11 inches is formed into an open-top box by cutting squares with side length x from each corner and folding up the sides. a. Find a formula for the volume of the box in terms of x b. Find the value for x that

*asked by Joey on April 29, 2016* -
## Pre calculus

How do I solve this exponent problem? I understand the exponent rules, but I getting 1 but 1 is not the answer! I don't want anyone to solve the problem for me, I want to learn how to solve this type of problem. Thank you! Solve the equation: -8=-3-6

*asked by anon on March 27, 2013* -
## pre calculus

For a given right triangle, side a = 400 feet and side b = 900 feet.What is the measure of angle A to the nearest degree?

*asked by Kelsey on November 30, 2012* -
## Pre Calculus

When doctors prescribe medicine at equally spaced time intervals, they are aware that the body metabolizes the drug gradually. After some period of time, only a certain percent of the original amount remains. After each dose, the amount of the drug in the

*asked by HanuMath25/11 on November 25, 2012* -
## Pre calculus

4x^2-25y^2-8x-100y-196=0 how do i find the conic section to find the center?

*asked by bbb on March 26, 2010* -
## Pre calculus

ramp needs an angle of elevation no greater than 4.8. the business has 8 ft to build the ramp. the ramp must rise 6 inches above the ground. can a ramp be built in this space? if a ramp can be built what is the minimum horizontal distance possible? please

*asked by Anonymous on March 2, 2017*