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The latest questions and answers, from members following Math at eNotes.Wed, 28 Jan 2015 17:28:50 PSTen-usThe range definition `t in [-pi/2,pi/2]` ``should only appear in...
http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976
The range definition `t in [-pi/2,pi/2]` ``should only appear in question 4) and not in question 3).http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976Wed, 28 Jan 2015 17:28:50 PSTThe question is asking for solutions to the given differential equations...
http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976
The question is asking for solutions to the given differential equations in each case, where the initial value is given (that is, they are Initial Value Problems). If a solution does indeed exist we are asked whether it is unique or not. 1) `dx/dt = sgn(x)` where `x(0) = 0` 'sgn' is the sign or signum function, which is +1 when the variable is positive and -1 when the variable is negative. So here when x<0 we have that `dx/dt = -1`...http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976#1Wed, 28 Jan 2015 17:25:32 PST1) dx/dt=sgn(x), x(0) =0; 2) dx/dt=sgn(t), x(0)=0; 3)...
http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976
1) dx/dt=sgn(x), x(0) =0; 2) dx/dt=sgn(t), x(0)=0; 3) dx/dt=3*x^(2/3), x(0) =0; 4) dx/dt=1+x^2 t={-pi/2 pi/2} Find solutions of the form x = f(t) where (f is a one-one function) in each case if any exist and state whether there is a unique solution.http://www.enotes.com/homework-help/1-dx-dt-sgn-x-x-0-0-2-dx-dt-sgn-t-x-0-0-3-dx-dt-3-473976#2January 28, 2015, 4:03 pm PSTAnother way of solving the system of equations 2x + y = 2 ...(1) 3x +2y...
http://www.enotes.com/homework-help/2x-y-2-3x-2y-5-solve-algebraically-470727
Another way of solving the system of equations 2x + y = 2 ...(1) 3x +2y = 5 ...(2) is using the elimination method. First, let's determine x by eliminating y. 2*(1) - (2) 4x + 2y - 3x - 2y = 4 - 5 x = -1 Now, determine y by eliminating x. 3*(1) - 2*(2) 6x + 3y - 6x - 4y = 6 - 10 -y = -4 y = 4 The solution of the given system of equations is x = -1 and y = 4http://www.enotes.com/homework-help/2x-y-2-3x-2y-5-solve-algebraically-470727Wed, 28 Jan 2015 13:29:38 PSTThe equation that you have to draw a graph of is y = (5/2)*x - 4. This...
http://www.enotes.com/homework-help/how-graph-y-5-2x-4-473798
The equation that you have to draw a graph of is y = (5/2)*x - 4. This is the equation of a straight line in slope-intercept form y = mx + c. Here, the slope of the line us 5/2 and the y-intercept is -4. A straight line is uniquely defined if two points that lie on the line are known. Consider the points with x-coordinate equal to 0 and the y-coordinate equal to 0. When x-coordinate is 0, y = 0 - 4 = -4 and when the y-coordinate is 0, 0 =...http://www.enotes.com/homework-help/how-graph-y-5-2x-4-473798Wed, 28 Jan 2015 13:23:36 PSTThere are correction for the solution above. It should have been :...
http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974
There are correction for the solution above. It should have been : a) Critical number of x=4 We consider f(0)=2 which is at the LEFT of x=4 and f(6) =-3 which is at RIGHT of x=4. According to the first derivative test, this shows that there is a relative maximum at x=4. b) Critical number of x=9. We consider f(6)= -3 which is at the LEFT of x=9 and f(10)=-5 which is at the RIGHT of x=9. This shows that there is "no sign change of...http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974Wed, 28 Jan 2015 13:21:47 PSTAccording to the first derivative test, the relative extrema can be...
http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974
According to the first derivative test, the relative extrema can be classified as: 1. Relative minimum if f'(x) = negative from the left of x=c and f'(x) = positive to the right of x=c. 2. Relative maximum if f'(x) = positive from the left of x=c and f'(x) =negative to the right of x=c. 3. If there is no sign change for f'(x) from the left and right of x=c, then f(x) is not a relative extrema of f. Solution: For critical number x=4, we...http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974#3Wed, 28 Jan 2015 07:07:12 PSTTo support the above answer, using calculus is another way to solve this...
http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970
To support the above answer, using calculus is another way to solve this such that, from the derived equation for area in this question: `A=1000l-2l^2` as `A'=0` for the maximum area and `A= 1000l -2l^2` (as explained above) `therefore A'=1000- 4l` `therefore 0=1000-4l` `therefore 4l=1000` `l=250` Substitute: `therefore w=1000-2(250)` `w=500` Substitute: `therefore area = 250 times 500` Ans: Maximum Area=125 000 ft^2http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970Wed, 28 Jan 2015 06:51:33 PSTa differential function f has critical numbers at x=4 and x=9. identify...
http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974
a differential function f has critical numbers at x=4 and x=9. identify all relative extrema of f at each of the critical points if f'(0)=2, f'(6)=-3 and f'(10)=-5.http://www.enotes.com/homework-help/differential-function-f-has-critical-numbers-x-4-473974#4January 28, 2015, 6:32 am PSTThe total amount of fencing is` 1000` ft, we will take note of the...
http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970
The total amount of fencing is` 1000` ft, we will take note of the formula for the Perimeter of a rectangle. We know that the formula for the Perimeter of a rectangle is:`P = 2L + 2W` For this problem one side is for a building, so the formula that we will consider is:`P = L + 2W` Since we are given with` 1000` ft for fencing the equation will be `1000 = L + 2W` (first equation)We are maximizing the area of it, so we will consider the formula...http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970#5Wed, 28 Jan 2015 05:52:00 PSTWe know that `xy = 20` and therefore we can estimate by using the...
http://www.enotes.com/homework-help/find-two-positive-numbers-that-satisfy-following-473969
We know that `xy = 20` and therefore we can estimate by using the factors of 20, what our answer will approximate to. From the factors, 1 x 20, 2 x 10, 4 x 5, we can already see that `x~~ 5` and `y~~ 4` giving us `2(5) + 3(4) = 22` . Now we use calculus to find the actual answer. Substitute a value for y such that if `xy=20` , `therefore y=20/x` and substituting that into `2x+3y` , `therefore = 2x + 3(20/x)` . Using the rules of exponents:...http://www.enotes.com/homework-help/find-two-positive-numbers-that-satisfy-following-473969Wed, 28 Jan 2015 04:54:57 PSTThe management of a large store has 1000 feet of fencing to enclose a...
http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970
The management of a large store has 1000 feet of fencing to enclose a rectangular storage yard using the building as one side of the yard . If the fencing is used for the remaining 3 sides, find the area of the largest possible yard.http://www.enotes.com/homework-help/management-large-store-has-1000-feet-fencing-473970#6January 28, 2015, 3:54 am PSTFind two positive numbers that satisfy the following: if xy=20, find...
http://www.enotes.com/homework-help/find-two-positive-numbers-that-satisfy-following-473969
Find two positive numbers that satisfy the following: if xy=20, find the minimum value of 2x+3yhttp://www.enotes.com/homework-help/find-two-positive-numbers-that-satisfy-following-473969#7January 28, 2015, 3:44 am PSTIf we are finding the sample standard deviation, we will apply the...
http://www.enotes.com/homework-help/what-process-finding-standard-deviation-after-have-473959
If we are finding the sample standard deviation, we will apply the formula: `s = sqrt((x - barx)^2/(n-1))` where `barx` is the sample mean` ` If we are finding the population standard deviation, we will apply the formula: `sigma = sqrt((x - mu)^2/(n-1))` where `mu` is the population mean When we already have a data to find the standard deviation of, we will first find the mean.The formula for the mean is: `barx = (sumx)/(n)` Then, we will...http://www.enotes.com/homework-help/what-process-finding-standard-deviation-after-have-473959Tue, 27 Jan 2015 23:45:10 PSTI am unsure what you are asking for, however I will assume you are...
http://www.enotes.com/homework-help/n-5n-473960
I am unsure what you are asking for, however I will assume you are asking`n+5n=?` To solve this you must search for all like terms, in this case the two monomials n and 5n. The blank space in front of the solitary n is actually a 1, as we still consider there to be one n in the problem. If we insert this 1 we get: `1n+5n=?` When adding monomials, add their constants together, in this case 1 and 5. Adding these together you get 6n as your...http://www.enotes.com/homework-help/n-5n-473960Tue, 27 Jan 2015 23:18:00 PST