# pre-calculus

Popular questions-
## Pre-Calculus

The formula D= 5e ^-0.4h can be used to find the number of milligrams D of a certain drug that is in a patient's bloodstream h hours after the drug has been administered. When the number of milligrams reaches 2, the drug is to be administered again. WHat

*asked by Erica on October 10, 2006* -
## pre-calculus

A Ferris wheel is boarding platform is 1 meters above the ground, has a diameter of 70 meters, and rotates once every 5 minutes. How many minutes of the ride are spent higher than 44 meters above the ground?

*asked by syd on April 7, 2019* -
## Pre-calculus

Complete the table assuming continuously compounded interest. (Round your answers to two decimal places.) Initial Investment: Annual % Rate: Time to Double: 8 yr Amount After 10 Years: $1700 I don't understand how to get in the initial investment of annual

*asked by Sarah on October 11, 2015* -
## pre-calculus

The High Roller Ferris wheel in Las Vegas, the tallest in the world, is elevated 2 m above ground. When a car reaches the highest point on the ferris wheel, its altitude from ground level is 168 m. How far away from the center, horizontally, is the car

*asked by bruh moment on July 29, 2020* -
## pre-calculus

x^2+6x+8y=7 Find the: Direction: Vertex: Focus: Axis of Symmetry: Directrix:

*asked by Leona on June 19, 2017* -
## Pre-Calculus

Find all of the fifth roots of 32i?

*asked by Joshua on March 29, 2018* -
## Pre-Calculus

A parallelogram has adjacent sides 7 cm and 15 cm. If the shorter diagonal is 10 cm long, find the length of the longer diagonal.

*asked by starmario12 on November 10, 2015* -
## Pre-Calculus

A ball is thrown vertically upward with an initial velocity of 64 feet per second. The distance(in feet) of the ball from the ground after t seconds is s=64t-16t. At what time will the ball strike the ground? For what time t is the ball more than 28 feet

*asked by Cicley on November 23, 2012* -
## Pre-Calculus

a ferris wheel is elevated 1 meter above ground. When car reaches the highest point of the Ferris wheel, it's altitude from ground level is 31 metres. How far away from the center, horizontally, is the car when it is at an altitude of 25 meters?

*asked by Shane on June 8, 2017* -
## Pre-Calculus

The Period T, in seconds, of a pendulum depends on the distance, L, in meters, between the pivot and the pendulum's centre of mass. If the initial swing angle is relatively small, the period is given by the radical function T=2pi(sqrtL/g) where g

*asked by Tyson on September 20, 2013* -
## Pre-Calculus

A ladder leans leans against a building that has a wall slanting away from the ladder at an angle of 96 degrees with the ground. If the bottom of the ladder is 23 feet from the base of the wall and it reaches a point 52 feet up the wall, how tall is the

*asked by K.C on March 4, 2011* -
## Pre-calculus

A ball is thrown from an initial height of 1 meter with an initial upward velocity of 9 m/s. The ball's height h (in meters) after t seconds is given by the following h=1+9t-5t^2 Find all the values of the t for which the ball's height is 4 meters.

*asked by Lucie on July 2, 2017* -
## Pre-Calculus

The cup on the 9th hole of a golf course is located dead center in the middle of a circular green that is 70 ft in diameter. You ball is located 50 feet south, and 40 feet west of the cup. The ball follows a straight line path and exits the green at the

*asked by Anonymous on October 4, 2015* -
## Pre-calculus

prove sin(x+y)+sin(x-y)/cos(x+y)+cos(x-y)=tanx

*asked by liv on November 19, 2016* -
## Pre-Calculus

An investor has $100,000 to invest in three types of bonds: short-term, intermediate-term, and long-term.How much should she invest in each type to satisfy the given conditions? Short-term bonds pay 4% annually, intermediate-term bonds pay 5%, and

*asked by Frank on February 28, 2016* -
## Pre-Calculus

Find all solutions to the equation in the interval [0, 2pi) cos4x-cos2x=0 So,this is what i've done so far: cos4x-cos2x=0 cos2(2x)-cos2x (2cos^2(2x)-1)-(2cos^2(x)-1) No idea what to do next.

*asked by Maria on March 19, 2012* -
## Pre-Calculus

After leaving an airport, a plane flies for 1.75h at a speed of 200km/h on a course of 100 degrees. The plane then flies for 2 hours at a speed of 250km/h on a course of 40 degrees. At this time, how far from the airport is the planee?

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

Here is correct question: Solve sin (pi/4*(x-6))=0.5, 0

*asked by Hanu on January 11, 2014* -
## Pre-calculus

Jana hit a golf ball with an initial velocity of 102 feet per second at an angle of 67° with the horizontal. After 2 seconds, how far has the ball traveled horizontally?

*asked by Becca on February 19, 2013* -
## Pre-Calculus

Driving down Bald Mountain in Wyoming, Bob dean finds that he descends 1600 feet in elevation by the time he is 2.5 miles (horizontally) away from the high point on the mountain road. Find the slope of his descent (Hint: 1 mile = 5280 feet) After

*asked by Caroline on January 10, 2013* -
## Pre-Calculus

If a varies directly as the square of b and inversely as the cube of c , how does the value of a change when the values of both b and c are halved? a remains the same a is halved a doubles a is 25% of its original value

*asked by Quinn on April 8, 2019* -
## Pre-Calculus

Suppose a daredevil attempted to jump a canyon, using a special rocket built for the stunt. Suppose it was launched off a ramp shown in the picture. The ramp was 325 feet in length and rose vertically 225 feet. (a) Calculate the measure of the angle of

*asked by Abby on April 13, 2018* -
## Pre-calculus

Prove the following identities. 1. 1+cosx/1-cosx = secx + 1/secx -1 2. (tanx + cotx)^2=sec^2x csc^2x 3. cos(x+y) cos(x-y)= cos^2x - sin^2y

*asked by Liv on November 18, 2016* -
## Pre-Calculus

If sin(theta)=15/17 and cos(beta)=(-5/13 (both theta and beta are in quadrant II) find tan(theta+beta)

*asked by Riley on November 14, 2010* -
## Pre-Calculus

f(x) = cos(x) on the interval [−2π, 2π] (a) Find the x-intercepts of the graph of y = f(x). (Enter your answers as a comma-separated list.) (b) Find the y-intercepts of the graph of y = f(x). (Enter your answers as a comma-separated list.) (c) Find the

*asked by Sam on November 29, 2015* -
## pre-calculus

Express the edge length of a cube as a function of the cube's diagonal length d. Then express the surface area and volume of the cube as a function of the diagonal length.

*asked by Christy on January 12, 2014* -
## Pre-Calculus

Solve the equation on the interval [0,2pi). 2sin^2x-3sinx+1=0 (2sinx+1)(sinx+1) I don't think I did the factoring correctly. When I multiply it out to double check I get 2sin^2x+3sinx+1

*asked by Jan on October 27, 2017* -
## Pre-Calculus

If θ represents an angle such that sin2θ = tanθ - cos2θ, then sin θ - cosθ = A. -√2 B. 0 C. 1 D. 2√2 What equation can I use to solve this problem?

*asked by Peter on July 31, 2012* -
## Pre-Calculus

Find the area of the triangle. Round to the nearest tenth. B= 42.8° a= 12.7 c= 5.8 I found b by using the Pythagorean theorem and got b= 11.298 but I don't know what to do next after this. I would find the altitude but I don't know angles A and C?

*asked by Vincent on November 29, 2009* -
## PRE-CALCULUS

AN OPEN BOX IS FORMED BY CUTTING SQUARES OUT OF A PIECE OF CARDBOARD THAT IS 16 FT BY 19 FT AND FOLDING UP THE FLAPS. WHAT SIZE CORNER SQUARES SHOULD BE CUT TO YEILD A BOX THAT HAS A VOLUME OF 175 CUBIC FEET

*asked by ASHLEY on September 6, 2009* -
## Pre-calculus

prove the identity sin2x-sin2y/sin2x+sin2y=tan(x-y)/tan(x+y)

*asked by liv on November 19, 2016* -
## Pre-Calculus

The minute hand of a clock is 3 inches long. How far does the tip of the minute hand move in 5 minutes? If necessary, round the answer to two decimal places.

*asked by Chris on September 10, 2016* -
## Pre-Calculus

Find a polynomial of degree 4 that has a integer coefficients and zeros 1,-1,2 and 1/2 (one half)?

*asked by Andrea on September 14, 2014* -
## Pre-Calculus

A road sign at the top of a mountain indicates that for the next 4 miles the grade is 12%. Find the angle of the grade and the change in elevation for a car descending the mountain.

*asked by Henry on February 5, 2009* -
## pre-calculus

which of the following is a solution to 3tan^3x=tanx? A.) 60 degrees B.) 120 degrees c.)150 degrees D.)240 degrees E.)300 degrees

*asked by Daisy on July 27, 2015* -
## pre-calculus

What is the exact value of sin 225

*asked by Daisy on July 27, 2015* -
## Pre-Calculus

Two polynomials P and D are given. Use either synthetic or long division to divide P(x) by D(x),and express the quotient P(x)/D(x) in the form P(x)D(x) = Q(x)+ R(x)D(x) . P(x) = 6x4 − 3x3 + 29x2, D(x) = 3x2 + 13

*asked by Jose on September 14, 2014* -
## Pre-calculus

C=80,000p/(100-p) A)what happens of the company tries to remove 100 percent of the pollutants? Will it work or will it cost too much? B)draw a diagram to show what the consequences of the last question would be. Label the verticals asymptote(s) and analyze

*asked by Aminata on February 21, 2014* -
## Pre-Calculus

74. Road Grade When driving down a mountain road, you notice warning signs indicating that it is a "12% grade." This means that the slope of the road is -12/100. Approximate the amount of horizontal change in your position if you note from elevation

*asked by Sam on February 3, 2011* -
## Pre-Calculus

A rectangular window is topped with a semicircle. The height of the rectangular part is 1 more than 3 times its width, w meters. Which function represents the total area, A, of the window in terms of the width?

*asked by Caitlin on September 10, 2015* -
## Pre-Calculus

1. A projectile is fired straight up from a height of 6 feet. Its height (h) in feet after t seconds is given by h = 6 + 192t -16t^2. Answer: h = -16t^2 + 192t + 6 h = -16( t^2 -12t +36) + 6 +576 h = -16 (t-6)^2 +582 The maximum height will be 582 feet. 2.

*asked by Lucina on March 16, 2015* -
## Pre-Calculus

Help please, am i correct? The border line of the linear inequality 4x-2y < 1 is solid. True False

*asked by Anonymous on September 24, 2014* -
## Pre-Calculus

A rectangle is bounded by the x-axis and the semicircle y = √36 – x2, as shown in the figure below. Write the area A of the rectangle as a function of x, and determine the domain of the area function. A = all real numbers except x = 36 all real numbers

*asked by Amanda on October 2, 2011* -
## Pre-Calculus

I need help with this problem: The bearing from the Pine Knob fire tower to the Colt Station fire tower is N 65 degrees E, and the two towers are 30 kilometers apart. A fire spotted by rangers in each tower has a bearing of N 80 degrees E from Pine Knob

*asked by Sharon on April 2, 2008* -
## Pre-Calculus

If sinA=3/5 when pi/2 < A < pi and cosB=5/13 when 3pi/2 < B < 2pi, find the exact value of the function cos(5pi/6+B).

*asked by Serein on April 1, 2020* -
## Pre-Calculus

A parabolic satellite television antenna has a diameter of 16 feet and is 2 foot deep. How far is the focus from the vertex? is the answer 8ft?

*asked by Jordan on August 21, 2019* -
## Pre-Calculus

A hemispherical bowl with a 30-centimeter radius contains some water, which is 12 centimeters deep. Find the volume of the water.

*asked by Danny on October 10, 2016* -
## Pre-Calculus

Use a calculator to approximate two values of theta (0

*asked by Sade on September 27, 2016* -
## pre-calculus

Choose the point on the terminal side of -210°.

*asked by Gabb7 on July 13, 2016* -
## Pre-Calculus

suppose y is directly proportional to x. if y=6 when x=4, find the constant of proportionality and write the formula for y as function of x. Use your formula to find x when y=8.

*asked by Monica on April 27, 2016* -
## Pre-Calculus

Let f(x) be the function 1/(x+9). Then the quotient [f(5+h)−f(5)]/h can be simplified to −1/(ah+b). What does a and b equal to? So I understand the overall concept, and did f(5+h) = 1/(14+h) and f(5) = 1/14. Then to subtract the two, you get the common

*asked by Ann on October 18, 2013* -
## pre-calculus

How do I prove that sinx/sinx+cosx=tanx/1+tanx

*asked by tatiana on October 3, 2011* -
## pre-calculus

Graph each complex number. Then express it in rectangular form. 2(cos(4pi/3) + isin(4pi/3)) I don't understand where to go from here.

*asked by Tom on March 9, 2010* -
## pre-calculus

While pulling a stalled car, a tow truck's cable makes an angle of 50 degrees above the road. If the tension on the tow truck's cable is 1600 newtons, how much work is done by the truck on the car pulling it 1.5 kilometers down the road? The answer is

*asked by Christa on February 21, 2010* -
## pre-calculus

An open box is made from a square piece of material 36 inches on a side by cutting equal squares from the corners and turning up the sides. Use your calculator to find the maximum volume this box can hold. I got the equation 4x^3-36x^2+1296x = V But when I

*asked by perry on September 18, 2009* -
## Pre-calculus

solve 4 sin^2x + 4 sqrt 2 cos x-6=0 for all real values of x. Going by the example in the book I got to: 4 cos^2x + 4sqrt2 cosx -10 = 0 but do not know how to proceed. Any help would be great. Thanks

*asked by Lucy on October 13, 2008* -
## Pre-Calculus

Consider a class with 10 sophomores, 8 juniors, and 6 seniors. Two students are selected at random. 1) What is the probability of selecting 1 junior and 1 senior. 2) Find the odds of selecting two students who are not seniors. How do I set these up to

*asked by Lucy on September 14, 2008* -
## Pre-Calculus

Verify the following identity: (sin2x)/sin - (cos2x)/cosx=secx

*asked by Serena on April 2, 2020* -
## Pre-Calculus

Which is the polar form of the parametric equations x=5cos(theta) and y=5sin(theta) ? a. r= 5(theta) b. r= 5 c. r= 25 cos (theta) sin (theta)***** d. r= 25cos^2 (theta) + 25sin^2 (theta) Which is the polar form of the parametric equations x=4t and y=t^2?

*asked by Vsuf on May 22, 2018* -
## pre-calculus

A rectangular box has a perimeter of 50 inches. Find the length and width of the box that would give the maximum area. Find the maximum possible area of the box.

*asked by Sam on December 12, 2016* -
## Pre-calculus

Find the equation of the locus of the point which moves so that its distance from the point (2,0) is 2/3 its distance from the line y=5.

*asked by Ace on August 31, 2016* -
## Pre-Calculus

Water is spraying from a nozzle in a fountain forming a parabolic path. The nozzle is 10 cm above the service of the water. The water achieves a max height of 100 cm above the waters surface and lands in the pool. The water spray is again 10 cm above the

*asked by Lucina on March 10, 2015* -
## Pre-calculus

Hello, Consider a geometric sequence with t3= 18 and t7= 1458. Are there one or two values for the common ratio? How does this affect the sequence (I got one, but the way this question mentions 2 ratios, I get the feeling there are 2 values.) My work: 1458

*asked by Lucina on February 12, 2015* -
## Pre-Calculus

Express the complex number in polar form. 5-12i

*asked by Alexis on March 15, 2014* -
## Pre-Calculus

The exponential function y(x)=Ce^ax satisfies the conditions y(0)=6 and y(1)=7. (a) Find the constants C and a. Enter the exact value of a. (b) Find y(2). Enter the exact answer. Simplify the answer so it does not contain any logarithms.

*asked by Becky on January 28, 2013* -
## Pre-Calculus

Which sets of ordered pairs represent functions from A to B? Explain. A = {a, b, c} and B = {0, 1, 2, 3} A. {(a, 1), (c, 2), (c, 3), (b, 3)} B. {(a, 1), (b, 2), (c, 3)} C. {(1, a), (0, a), (2, c), (3, b)} D. {(c, 0), (b, 0), (a, 3)} I narrowed it down to

*asked by Peter on August 9, 2012* -
## Pre-Calculus

A photogrpaher points a camera at a windows in a nearby building forming an angle of 42 degrees with the camera platform. If the camera is 52 meters from the building , how high above the platform is the window, to the nearest hundreth of a meter. The

*asked by K.C on March 10, 2011* -
## pre-calculus

A man who can row in still water at 3 mph heads directly across a river flowing at 7 mph. At what angle to the line on which he is heading does he drift downstream and at what speed does he drift downstream?

*asked by ruca on March 17, 2010* -
## pre-calculus

A missile is fired at an angle of 75 from the horizontal. At one point, its speed was 900 mph. Find its horizontal velocity in miles per minute. (Round to the nearest hundredth.)

*asked by brenden on March 17, 2010* -
## Pre-calculus

From a circular piece of metal sheet with diameter 20 cm, a rectangular piece with perimeter 28 cm is to be cut as shown. Find the dimensions of the rectangular piece.

*asked by Yna on November 27, 2018* -
## Pre-Calculus

Verify the identity. (csc(2x) - sin(2x))/cot(2x)=cos(2x) =csc(2x)/cot(2x) - sin(2x)/cot(2x) =csc(2x)/cot(2x) - cos(2x) Is this correct so far? If so then how would I continue? I got stuck on this part...

*asked by Karry on September 28, 2017* -
## pre-Calculus

find the remainder when (x^40 -3) is divided by (x+1)

*asked by Tod on March 16, 2017* -
## Pre-Calculus

How do I solve the equation: 3 = 2.1 sin[(pi/6)t - 5pi/6] + 3.2

*asked by Brian on February 19, 2017* -
## pre-calculus

A rectangular box has a perimeter of 36 inches. Find the length and width of the box that would give the maximum area. e. l = 9, w = 9 f. l = 81, w = 9 g. l = 27, w = 9 h. l = 18, w = 18

*asked by Sam on December 12, 2016* -
## Pre-Calculus

Convert to Rectangular: r*tan theta/sec theta=2 A. y=2 B. y=1/2 C. x=2 D. x=1/2

*asked by Sade on December 2, 2016* -
## PRE-CALCULUS

. Sam won $150,000 in the Michigan lottery and decides to invest the money for retirement in 20 years. Find the accumulated value for Sam’s retirement for each of his options: (a) a certificate of deposit paying 5.4% compounded yearly (b) a money market

*asked by ROSE on November 18, 2016* -
## Pre-Calculus

A drawbridge is l = 110 feet long when stretched across a river. As shown in the figure below, the two sections of the bridge can be rotated upward through an angle of α = 34°. a)If the water level is 35 feet below the closed bridge, find the distance d

*asked by Tim on February 25, 2016* -
## Pre-calculus

Hi i need to find x in 9^(2x-6)=6^(8x-5) So what i did was: 3^(4x-12)=6^(8x-5) log3(3)^(4x-12)=log3(6)^(8x-5) 4x-12=(8x-5)log3(6) now i'm stuck. and i actually feel that the whole thing is wrong. help, pls

*asked by Lid on October 9, 2015* -
## pre-calculus

find the exact value of sin 112.5 in fraction form

*asked by Daisy on July 27, 2015* -
## Pre-Calculus

Write the polar equation in rectangular form... r=5sintheta

*asked by Alexis on March 13, 2014* -
## Pre-Calculus

Composition of Functions If f(x) = 2x+1 find A. f o f(x) f(f(x)) = f(2x+1) f(2x+1) = 2(2x+1) f(f(x)) = 4x +2 B. f o f o f o f(x) ^ I don't get how to solve this one C. f o f o f o f o f ...o f(x) n functions of f ^ I also don't get how to solve this one

*asked by Shreya on September 27, 2012* -
## Pre-Calculus

How do I find the minimum or maximum of this y = 2x³ + 3x² - 12x? It makes 2 curves.

*asked by Peter on August 11, 2012* -
## Pre-Calculus

Determine the open intervals on which the function is increasing, decreasing, or constant. f(x) = 3 f(x) = x^(2/3) f(x) = -x^(3/4)

*asked by Peter on August 11, 2012* -
## pre-calculus

suppose a triangle has two sides of lengths a and b. if the angle between these sides varies, what is the maximum possible area that the triangle can attain? what can you say about the minimum possible area? could you explain by detail

*asked by tatiana on September 29, 2011* -
## Pre-Calculus

A salesman's monthly commission is 15% on all sales over $12000. If his goal is to make a commission of at least $3000/month, what minimum monthly sales figures must he attain?

*asked by Step on May 26, 2011* -
## pre-calculus

Prove 3+4+5+...+(n+2) = [n(n+5)]/2 for n>4 Do the first step in a proof by induction.

*asked by James on June 21, 2010* -
## pre-calculus

What is the polar form of the equation 3x - 4y = 12? The answer is r = 12/ (3cosx - 4 sinx) (x = theta) I don't know how to get the answer though.

*asked by Jamie on April 6, 2010* -
## Pre-calculus

State the period, phase shift, and vertical shift of the function y=tan(theta/2-pi/4)+3. Is this right? ANSWER: period:2pi phase shift:-pi/4 vertical shift:3

*asked by Mary on January 21, 2009* -
## Pre-calculus

A set of data is normally distributed with a mean of 500 and standard deviation of 40. a). What percent of the data is between 460 and 540? P(460

*asked by Mary on January 16, 2009* -
## Pre-Calculus

Two cards are drawn from a standard deck of 52 cards. What is the probability of drawing 2 queens or 2 red cards? (4/52)(3/51)=1/221 ---drawing a queen (26/52)(25/51)=25/102--drawing a red card (1/221)(25/102)= 25/22542 drawing a queen or red card Is this

*asked by Lucy on September 17, 2008* -
## Pre-Calculus

A car manufacturing company (the Company) can produce a car for $3000.00 and a truck for $5000.00. Suppose "C" cars and "T" trucks are sold to the dealer at mark-ups, respectively, of 20 and 30 percent. If the Company made a profit of $27 million on sales

*asked by Andrea on July 24, 2008* -
## Pre-Calculus

Find the period and, where appropriate, the amplitude of the following function: y=2sin(x)

*asked by Daisy on April 6, 2008* -
## pre-calculus

Initially 700 milligrams of a radioactive substance was present. After 2 hours the mass had decreased by 5%. Construct an exponential model A(t) = A0ekt for the amount remaining of the decaying substance after t hours. Find the amount remaining after 24

*asked by Maddie on April 16, 2020* -
## pre-calculus

the profit of a company, in dollars, is the difference between the company's revenue and cost. the cost C(x), and R(x) are functions for a particular company. the x represents the number of items produced and sold to distributors. C(x)=2000+60x

*asked by jill on January 28, 2020* -
## Pre-Calculus

In the Adirondack Mountains near Tupper Lake, New York, forest fire observers used fire observation towers for over 70 years. The people who staffed the towers reported forest fires and smoke sightings. As many as 57 towers were used by the observers;

*asked by Abby on April 13, 2018* -
## Pre-Calculus

Use applications of exponential functions and logarithmic functions to solve. The half-life of plutonium 241 is 14.4 years.If 100 grams is present now, How much will it take to reach 2 grams of plutonium 241? y=a(1/2)^(t/14.4) How do I solve for t? I'm not

*asked by Suga on December 14, 2017* -
## Pre-calculus

Hi, How do I simplify and state the restrictions on the following: 12x^8y^9 / 3x^4y^6 what do I need to factor out? I'm so confused, I never know what I'm allowed to factor out.

*asked by Sarah on September 26, 2017* -
## Pre-Calculus

A drug manufactured by a pharmaceutical company is sold in bulk at a price of $150 per unit. The total production cost (in dollars) for x units in one week is C(x) = 0.02x^2 + 100x + 3000. How many units of the drug must be manufactured and sold in a week

*asked by Andy on July 19, 2017* -
## Pre-calculus

Find the center radius and equation of a circle in standard form given the following conditions: 1. Tangent to 3x+2y=0 at the point (0,0) and passing through (1,-1) and (6,0)

*asked by chen on July 2, 2017* -
## Pre-Calculus

The cost of sending a package overnight is $14.40 for the first pound and $3.90 for each additional pound or portion of a pound. A plastic mailing bag can hold up to 3 pounds. The cost f(x) of sending a package in a plastic mailing bag is given by the

*asked by Iris on December 12, 2016*