# Ray

Questions and answers by visitors named Ray

## Questions

1. ### A car was valued at $38,000 in the year 2003. The value depreciated to$11,000 by the year 2009. Assume that the car value continues to drop by the same percentage.

-What will the value be in the year 2013?

2. ### What is the limit of g(x)=x as x approaches pi?

Would it just be pi??

3. ### 1.630 g of iron ore is dissolved in an acidic solution. This solution is titrated to a pink endpoint with 27.15 mL of a 0.020 M KMnO4 solution.

a. How many moles of MnO4- ions were consumed? b. How many moles of Fe2+ were in the iron ore sample? c. What is

4. ### A company introduces a new product for which the number of units sold S is given by the equation below, where t is the time in months.

s(t)=155(7-9/(2+t)) a) Find the average rate of change of s(t) during the first year. Which my answer was 1395/28 b)

5. ### 1. Three resistors are placed in series. They have the following resistances: R1 = 20 ohms, R2 = 20 ohms, R3 = 10 ohms. What current would be moved through this circuit by a 5-V power supply?

A. 1.0 A B. 0.10 A C. 25 A D. 250 A 2. Two resistors are placed

6. ### What is the difference between class limits and class boundaries?

A) Class limits are the numbers that separate classes without forming gaps between them. Class boundaries are the least and greatest numbers that can belong to the class. For integer data,

7. ### In how many different ways can six of ten people be seated

in a row of six chairs? I don't have the answer, but from my rough understanding of permutations and combinations, I got: 10C6 * 6! = 210 * 6! I figure first 6 people have to be chosen out of the

9. ### A truck with 40-in.-diameter wheels is traveling at 50 mi/h.

a) Find the angular speed of the wheels in rad/min b) How many revolutions per minute do the wheels make?

11. ### Evaluate the expression without using a calculator (Make a sketch of a right triangle)

tan(arccot 2) Thanks in advance! I'm trying to refresh my memory of these kinds of problems and I'm having trouble on how to solve this problem

45. ### A simple random sample of size n equals=3737 is obtained from a population with μ equals=6969 and σ equals=1515.

​(a) What must be true regarding the distribution of the population in order to use the normal model to compute probabilities involving the

48. ### The boy whose mother died is

around.What is the grammatical name and function.

51. ### A tractor and tow truck have rubber tires on

wet concrete. The tow truck drags the tractor at constant velocity while its brakes are locked. If the tow truck exerts a horizontal force of 1.0 x 10^4 N on the tractor, determine the mass of the tractor. Refer

54. ### Solve the system by graphing. (Enter your answers as a comma-separated list. If the system is inconsistent, enter INCONSISTENT. If the system is dependent, enter DEPENDENT.)

x + y = 4 x − y = 2 (x, y) =

57. ### Consider the the distribution of under-inflated tires on a four-wheel automobile. The mass

density is given by: p(0) = 0.4, p(1) = p(2) = p(3) = 0.1, p(4) = 0.3 a) Find the expected value and the variance of this distribution. b) For what proportion of such

59. ### What happened to airplane manufacturing after World War II?

1 Airplane manufacturers began producing goods for the oil industry. 2 Airplane manufacturing rebounded and produced airplanes, parts, and equipment. 3 Airplane manufacturing decreased in Texas as

60. ### How were prisoner of war camps different from internment camps?

1 Prisoner of war camps held fewer people than internment camps. 2 Prisoner of war camps held captured soldiers. 3 There was more freedom in prisoner of war camps. 4 Prisoner of war camps were

61. ### Egg-laying land animals have evolved to produce eggs with tough shells to ensure that

1 external fertilization can take place. 2 the egg and sperm can fuse 3 parental care is unnecessary*** 4 the developing embryo does no dry out

64. ### how did the decade of prosperity affect the lives of many Mexican-Americans in Texas

They became wealthier They became migrant laborers They Moved to other states They Entered New Industries My answer is the 3rd one please check that for me!

65. ### what efforts did james hogg make to fix the corporate world in Texas?

1 allowed railroads to choose the path of the rail lines 2 created laws against monopolies 3 made his own insurance company 4 made it easier to start companies

66. ### I am given a vector function <2cos(t) + cos(2t), 2sin(t) + sin(2t), 0>

(in other words) : (2cos(t) + cos(2t))i + (2sin(t) + sin(2t)j + 0k Compute the slope dy/dx and concavity d^2x/(dx^2) at t = pi/3. I understand that finding the slope of a vector is

67. ### Compute the area of the parallelogram formed by A(-2, 1, 4), B(0, -2, 3) C(-1, 6, 5), and D(1, 3, 4).

So for this problem, do I turn the four points into two vectors with AD and BC and then take the cross product and then find the magnitude? Taking the

69. ### Given the equation x + z = 2.

Is P parallel to any of the coordinate planes? Is P perpendicular to any of the coordinate planes?

71. ### I am trying to prepare for my finals and I'm approached with this question where I'm not entirely clear what the answer should be:

Given the function h(t) graphed below, define A(x) = ∫[-0.5,x] h(t) dt . (Graph is in the link)

72. ### I'm given the equation S = L(1 - e^(-kt))

I am asked to write S as a function of t when L = 100, S = 25 when t = 2 So would my final answer just have S and t as variables? Or have S, t and L as variables? Ended up with S = 100(1 - e^((ln(3/4)/2)*t) Or is

73. ### The rate of change in the number of miles s of road cleared per hour by a snowplow is inversely proportional to the depth h of snow. That is,

ds/dh = k/h Find s as a function of h given that s = 25 miles when h = 3 inches and s = 10 miles when h = 9 inches

74. ### Some of the curves corresponding to different values of C in the general solution of the differential equation are shown in the graph. Find the particular solution that passes through the point (0, 2).

y(x^2+y) = C 2xy + (x^2+2y)y' = 0 How would I start

75. ### Take the area enclosed by the curves y = sqrt(x), y = 1, and x = 4. Rotate it around the line x = 5. Find the volume.

While I understand the general problem would call for the shell method ∫[a,b] 2*pi*r*h dx With r = 5 - x and h = sqrt(x) - 1 But, what

76. ### Since sec^2θ - 1 = tan^2θ

I know this is trivial, but I want to make sure I'm doing this right before I apply it to the integral I'm trying to solve... If I have some constant a, (a^2secθ)^2 - (a^2)^2 If I wanted to change this to tan would it be:

77. ### I'm having trouble trying to solve for the partial fraction decomposition in order to find the integral.

∫ x / (x^4 - a^4) dx I'm assuming a is some constant in this case. So I factored the denominator to this: (x^4 - a^4) = (x^2 + a^2)(x + a)(x - a)

78. ### I am trying to understand my teacher's example of a Work problem.

Cut to the chase here's a picture of the problem: goo.gl/photos/AqZ6ENmHLg6heixD7 While I understand how to integrate fairly well, I'm still confused on how exactly my teacher set up the work

79. ### I am supposed to find the area of the region given two boundaries and two functions revolving about the x axis.

x = 0 x = pi/2 y = cos(x/2) y = sin(x/2) Graphing those two functions made me select to use the washer method. Therefore, I set my definite

80. ### Find ∫1/((x^2+5)^(3/2)) dx

I figured this would be a trig substitution problem, so I set x = sqrt(5)tanθ and dx = sqrt(5)sec^2(θ) dθ This would lead to: ∫(sqrt(5)sec^2(θ)) / (5tan^2(θ) + 5)^(3/2) dθ But I'm kinda lost on what to do next. I'm used

81. ### I would like to solve the ∫sin^2(pix) dx

Using the given substitution identity: sin^2(x) = (1/2)(1-cos2x) This is what I did so far: ∫sin^2(pix) let u = pix du = pi dx (1/pi)∫sin^2(u)du Applying the identity is where I'm lost on how to continue

82. ### ∫sin(x)cos(x) dx

Using the identity sin(2x) = 2 sin(x) cos(x)?

83. ### I am given an integral to solve with given substitution values. I got an answer, but I'm not quite sure if it's correct as an online integral calculator gave a different answer.

∫ x sqrt(4-x) dx Given that u = 4-x . In this case, x = 4 - u du = -dx Now..

84. ### Six and one-half foot-pounds of work is required to compress a spring 4 inches from its natural length. Find the work required to compress the spring an additional one-half inch. (Round your answer to two decimal places.)

This is what I did so far: 4 in =

85. ### Consider the graph of y^2 = x(4-x)^2 (see link). Find the volumes of the solids that are generated when the loop of this graph is revolved about (a) the x-axis, (b) the y-axis, and (c) the line x = 4.

goo.gl/photos/v5qJLDztqsZpHR9d7 I'm just having trouble

86. ### ∫ (2x-1)^2 dx could have two answers:

a) ((2x-1)^3)/6 + C b) 4/3x^3 - 2x^2 + x + C Now the question is, how are the two answers related? I attempted to answer the question by: "The two answers are related because when finding the derivative of those two

87. ### I am given two integrals a and b

a) ∫ 1/(1 + x^4) dx b) ∫ x/(1 + x^4) dx The main difference between the two integrals appears to be the "1" and "x" on the numerators. While they both resembles closely to the basic integration of arctan: ∫ du/(a^2 +

88. ### Find the indefinite integral in two ways.

∫(2x-1)^2 dx The first way I used was using the power rule and chain rule with substitution. Let u = 2x - 1 du = 2 dx (1/2)∫ u^2 du (Applying power rule) (1/2) * (u^3/3) + C =(2x-1)^3/6 + C What would be another

90. ### The area A between the graph of the function:

g(t) = 4 - (4/t^2) and the t-axis over the interval [1, x] is: A(x) = ∫[1, x] (4 - (4/t^2)) dt a) Find the horizontal asymptote of the graph g. I believe the horizontal asymptote of graph g is g(t) = 4. b)

91. ### Sketch the region given by the definite integral. Use geometric shapes and formulas to evaluate the integral (a > 0, r > 0).

r ∫ sqrt(r^2 - x^2) dx -r While I recognize that this looks similar to a circle function, I'm not sure how to graph and evaluate

92. ### Evaluate the integral using the following values.

8 ∫ x^3 dx = 1020 2 8 ∫ x dx = 30 2 8 ∫ dx = 6 2 2 ∫ x^3 dx = ? 2

93. ### Here is the link to the graph of f' in question:

bit.ly/2oml70V I have a hard time trying to answer these kinds of questions when we're only given a graph of f'. a) Approximate the slope of f at x = 4. Explain. I believe the slope of f in this case would be

94. ### In order to predict y-values using the equation of a regression line, what must be true about the correlation coefficient of the variables?

A. The correlation between variables must be an x-value of a point on the graph. B. The correlation between variables

96. ### The population of bacteria in a petri dish doubles every 12 h. The population of the bacteria is initially 500 organisms.

How long will it take for the population of the bacteria to reach 800? Round your answer to the nearest tenth of an hour.

99. ### Just giving this a shot,

Which of the following statements about RAM are TRUE? Select all that apply. a) Any part of RAM can be accessed at any time. b) RAM is an area of a computer that holds programs and data that are waiting to be processed, to be stored

100. ### If the average atomic mass of Br is 79.90 amu, what is the percent abundance of each of its isotopes?

How would we figure out the isotopes first before we calculate the percent abundance??

1. 1
2. 2
3. 3
4. 4