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Question 374485: I thought you used the formula -b+-sqroot b^2-4ac/2a My answer did not look right, please help!
Solve.
15x^4-11x^2+2=0
Click here to see answer by Alan3354(30993)

Question 374490: w^2+50w–6600=0
Click here to see answer by jim_thompson5910(28548)

Question 374567: write a quadratic equation in the variable x having the given numbers as solutions. SOLUTION: 2, ONLY SOLUTION
Click here to see answer by robertb(4012)

Question 374641: A rectangle is 9ft longer than its wide, and its area is 360ft2. use quadratic equation to find its length and width
Click here to see answer by mananth(12270)

Question 374408: Use the quadratic formula to find all roots: f(x)= 2x^3-3x^2-2x+3
Click here to see answer by ankor@dixie-net.com(15647)

Question 374913: Is this the solution to this problem:
2.Discriminant is zero. There is only one solution.
x = -b/2a

Click here to see answer by ewatrrr(10682)

Question 374923: Solve the equation x^2-4x=-10 and express the roots in terms of i.
Click here to see answer by Fombitz(13828)

Question 374974: Evening Everyone.
Been a while since i attempeted anything like this and trying to brush up a little, i have attempted to anser the first two parts if somebody would be so kind as to check them and assist on the third part

Use the chain rule to find the derivatives of the following functions:
(a) y = e^-x2
I Got = -2e^(-x^2)
(b) y = cos(3x^2 + 2x)
I Got = (-Sin).(3x^2+2x).(6x+2)
(c) y = sin^2(3x^2 - 1)
Thank You in antiscipation
Click here to see answer by Fombitz(13828)

Question 375002: Would really appreciate help with the following question on my task sheet.

Find dy=dx as a function of x and y when:
(a) y - x sin y - 3x^2 - 1 = 0
and
(ii) x^2y^3 - x^2 + 3y - 3 = 0
Finally
(c) (1 - x^2) tan^-1 y = 3
Need to brush up on these, have looked in engineering mathmatics book, having difficulty, and the instructor isnt really approachable
Thanks
Click here to see answer by Fombitz(13828)

Question 375008: HiPlease can somebody help with this problem i) The variables x and y are given in terms of the parameter t as x = 3t(1 + t^3) and y = 3t^2(1 + t^3). Provethat dy/dx = t(2 + 5t^3)/1 + 4t^3 ii) A cycloid is a curve traced out by a point on the rim of a wheel as it rolls along the ground. Its curve maybe given parametrically by x = a(t - sin t) and y = a(1 - cos t), where a is a constant. Show thatdy/dx = cot(t/2) Thanks
Click here to see answer by Fombitz(13828)

Question 375016: I don't know how to convert this equation into standard form (i'm completely lost):
150=w[(120-w)/2]
thank you
Click here to see answer by solver91311(16877)

Question 375026: 48-Y=X=128/Y
Click here to see answer by Fombitz(13828)

Question 375035: What 2 numbers have a product of 128 and a sum of 48?
I don't believe it has a solution with whole numbers anyway.

Click here to see answer by jim_thompson5910(28548)

Question 375015: Hi Totally Bewildered, Please Help?

The path of a point is given parametrically by x = a cos t, y = b sin t. Show that the point travels
around the ellipse
x^2/a^2 +y^2/b^2 = 1
Express dy=dx in terms of t. Suppose that t represents time. Express the speed as a function of t.
ii) A closed hollow vessel is in the form of a right-circular cone, together with its base, and is made of sheet
metal of negligible thickness.
Express the total surface area S in terms of the volume V and the semi-vertical angle 'theta' of the cone.
Show that for a given volume, the total area of the surface is a minimum if sin 'theta' = 1/3 . With this value of 'theta', find
the value of S if V = 8/3'pie' a^3 where a is a constant.
Sorry didnt know how to get symbols on this, so typed the names
Kind Regards
John
Click here to see answer by solver91311(16877)

Question 375065: Hello everyone, finding the following question puzzling, i have not covered this before, and am trying to get a heads up for when i start my course
Use logarithmic differentiation to differentiate the following:
(i) y = 2^x (ii) y = x^x
Cheers
Click here to see answer by jim_thompson5910(28548)

Question 375143: Solve the system of equations by graphing. Then clasify the system.
6u=v= 32
6u=v=40
Click here to see answer by robertb(4012)

Question 375143: Solve the system of equations by graphing. Then clasify the system.
6u=v= 32
6u=v=40
Click here to see answer by Alan3354(30993)

Question 375139: Solve the system of equations by graphing. Then classify the system.
6x-y=21
6x=7y=-3
Click here to see answer by Fombitz(13828)

Question 375243: how do solve: h(t) = -16t^2 + 90t + 15
Click here to see answer by nerdybill(6958)

Question 375234: x(2x+7)=0
Click here to see answer by Fombitz(13828)

Question 375377: What is -3x^2+12x in vertex form?
Click here to see answer by Fombitz(13828)

Question 375397: a student is asked to solve b^2+x^2=a^2 and gives the solution:x=a-b. What did they do wrong and how do you correctly solve this????

Click here to see answer by edjones(7569)

Question 375466: factor quadratic expression
3. 5x2 – 19x – 4
Click here to see answer by ewatrrr(10682)

Question 375465: factor each quadratic expression
2. 3x2 + 13x – 10

Click here to see answer by ewatrrr(10682)

Question 375464: solve the equation
5. x2 – 3x + 2 = 0
Click here to see answer by ewatrrr(10682)

Question 375468: factor quadratic expression
1. –8x2 + 32
Click here to see answer by ewatrrr(10682)

Question 375463: 4. x2 + 144 = 0 (1 point)
a. 12
b. ±12i
c. –12
d. ±12

Click here to see answer by ewatrrr(10682)

Question 375478: Hello Everyone
Having Trouble with this.

Evaluate:
dy=dx at x = 0 where
(i) y = (x^2 - 1)/(x^2 + 2x + 1)
(ii) y = (e^x + 1)/(1 + e^-x)
Thank You
Click here to see answer by Fombitz(13828)

Question 375404: Greetings Everyone,
A bit puzzelled with this poblem

Evaluate dy=dx at x = 0 where
(i) y = (x^2 - 1)/(x^2 + 2x + 1)
(ii) y = (e^x + 1)/(1 + e^-x)
Thanks in advance
Click here to see answer by Fombitz(13828)

Question 375527: 2. x2 – 2x – 11 = 0 Use the Quadratic Formula to solve each equation.

Click here to see answer by jim_thompson5910(28548)

Question 375527: 2. x2 – 2x – 11 = 0 Use the Quadratic Formula to solve each equation.

Click here to see answer by ewatrrr(10682)

Question 375858: Hi, Totally Stuck here, not sure if the lecturer has skiped over this part,
Find dy=dx as a function of x and y when:
(a) y - x sin y - 3x^2 - 1 = 0
(b) x^2y^3 - x^2 + 3y - 3 = 0
(c) (1 - x^2) tan^-1 y = 3
Thanks
Click here to see answer by Fombitz(13828)

Question 375885: Find a fourth degree polynomial function f(x) having only real coefficients,-1,4, and i as zeros, and f(2)=30
Click here to see answer by Fombitz(13828)

Question 375879: 3x^2 + 9x, find x and y intercepts,range and vertex.
Click here to see answer by Fombitz(13828)

Question 375879: 3x^2 + 9x, find x and y intercepts,range and vertex.
Click here to see answer by ewatrrr(10682)

Question 375514: find and label the vertex and the line of symmetry f(x)=-2(x+2)=0
Click here to see answer by Fombitz(13828)

Question 375827: -x^2-3x+5=0
Click here to see answer by jim_thompson5910(28548)

Question 375912: I am having trouble understanding this, can anyone please help?
Simplify the following expression, and rewrite it in an equivalent form with positive exponents.
-11x^4y^-2/55x^-5y^-1
Click here to see answer by Alan3354(30993)

Question 375874: I am having trouble wiyh my Appendix F. Can someone help me please?
Suppose you are an event coordinator for a large performance theater. One of the hottest new Broadway musicals has started to tour, and your city is the first stop on the tour. You need to supply information about projected ticket sales to the box office manager. The box office manager uses this information to anticipate staffing needs until the tickets sell out. You provide the manager with a quadratic equation that models the expected number of ticket sales for each day x. ( is the day tickets go on sale).
Tickets = x2 - 6x + 16
a. Does the graph of this equation open up or down? How did you determine this?
b. Describe what happens to the tickets sales as time passes?
c. Use the quadratic equation to determine the last day that tickets will be sold. (Note: Write your answer in terms of the number of days after ticket sales begin.)
d. Will tickets peak or be at a low during the middle of the sale? How do you know?
e. After how many days will the peak or low occur?
f. How many tickets will be sold on the day when the peak or low occurs?
g. What is the point of the vertex? How does this number relate to your answers in parts e and f?
h. How many solutions are there to the equation x2 - 6x + 16? How do you know?
i. What do the solutions represent? Is there a solution that does not make sense? If so, in what ways does the solution not make sense?

Click here to see answer by Earlsdon(6287)

Question 375940: Hi, the problem i am having is with subsitution in a qudratic equation.
x^2-xy=10 (1)
x+y=8 (2)
Thank you. I worked it out using the qudratic formula but i would like to know if it's right before handing my assignment in to my teacher I need it by tommrrow morning please help.
Click here to see answer by scott8148(6628)

Question 376000: 1-2x<5-x
Click here to see answer by robertb(4012)

Question 376022: what rate of interest would one need in order to double one's investment in 8 years if interest is compounded daily.
Click here to see answer by solver91311(16877)

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