# Posts by SARA

Total # Posts: 4,473

**astronomy**

^ and any number or combination of those can be chosen.

*April 5, 2015*

**astronomy**

Even though I do not believe the Big Bang is what created the universe(although what people clam the bing bang was would have been similar to what happened when God said "Let there be light" I still have astronomy hw. haha. I am having trouble with this question. The...

*April 5, 2015*

**linear algebra check**

Use the Gram-Schmidt process to transform the basis [1 1 1] , [0 1 1] , [2 4 3] for the Euclidean space R3 into an orthonormal basis for R3. (Enter each vector in the form [x1, x2, ...]. Enter your answers as a comma-separated list.) so i went through the process and got [1/...

*April 4, 2015*

**English**

i meant A

*April 2, 2015*

**calc**

how did you expand the determiannt

*April 2, 2015*

**calc**

If possible, find a, b, and c so that v = [a b c] is orthogonal to both w = [1 6 1] and x = [1 −9 1]

*April 2, 2015*

**engr**

what useful product can you make using recyclable items?

*April 1, 2015*

**AP Chemistry**

A 5.0 M solution of HNO3 is titrated with 0.3 M NaOH. Identify the species that have the highest concenttrations in the solution being titrated halfway to the equivalence point. A 25.15 ml of 0.35 m HNO3 was titrated with an unknown concentration of NaOH. The endpoint was ...

*March 29, 2015*

**math check**

determine whether the given vector A in M22 belongs to the span (a1,a2,a3) where a1=[1 -1; 0 3] a2=[1 1; 0 2] a3=[2 2; -1 1] and A=[5 1; -1 9] so I set up an augmented matrix , but im not sure if I set it up correctly. I made a1 a2 and a3 into columns. 1 1 2 | 5 0 0 -1 | -1 -1...

*March 28, 2015*

**statistics**

.1587

*March 27, 2015*

**AP Chemistry**

A buffered solution was created by mixing solutions of NH4Cl and NH3 at 25 C. Which species, NH4+ or NH3, has the highest concentration in this buffered solution?. Justify your answer.

*March 26, 2015*

**accounting**

If a business is purchased by the issue of 10000 $10 8% debentures trading at $95, how much is the purchase consideration? I did 10000x95, but the answer in the key is option D instead, 95000, not 950,000... I'm totally confused..

*March 25, 2015*

**Math.**

Half of Allan's test score plus eight equals 50. What did Allen score on his test?

*March 24, 2015*

**math**

When the equation of a line is written in general form, Describe the Slope of the line when A=0 or and B=0 ? Thanks!

*March 24, 2015*

**math**

Verify that the function satisfies the three hypotheses of Rolle's Theorem on the given interval. Then find all numbers c that satisfy the conclusion of Rolle's Theorem. (Enter your answers as a comma-separated list.) f(x) = 5 − 6x + 3x2, [0, 2] can someone ...

*March 23, 2015*

**Vectors**

How would I find the direction vector parallel to a line? For example, how is (2,1) a direction vector parallel to the line -x+2y-10=0

*March 20, 2015*

**Vectors**

determine the number of solutions, the generalized parametric solution, and explain why there are no integer solutions for the equation 2x+10y=31

*March 17, 2015*

**Vectors**

Can you please explain how to answer this? What is a solution for the following system? x-4y+z=2 and -x+4y-2z=8 a) x=4s+12, y=s, z=-10 b) x=s+4, y=3s, z=-4 c) x=2s+5, y=s, z=-12 d) x=s, y=4s, z=-12

*March 17, 2015*

**Vectors**

Multiple choice: Can you please explain how to answer this? Which point does not lie on the same plane as the points P(1,5,6), Q(-2,-3,4) and R(-1,3,2) a) S(0,4,4) b) S(4,13,8) c) S(0,-1,8) d) S(1,-3,2)

*March 17, 2015*

**Vectors**

What is the distance between the parallel lines having equations 2x+2y=16 and x+y=0 a) 16 b) 4 root 2 c) 2 d) 8 I got the answer 2. I solved for y in the 2x+2y=16 equation and got 8. that gave me point (0,8) I used the d= (ax+by+c)/root (a^2+b^2) using the equation x+y=0 and ...

*March 17, 2015*

**Vectors**

To answer this I would just sub in the x and y values right? I got a) as my answer since it equals 0. Which of the following would describe the sketch of the expression xy+2y-3x-6=0 a) the planes x=-2 and y=3 b) the planes x=3 and y=-2 c) the planes x=6 and y=2 d) the planes x...

*March 17, 2015*

**Vectors**

can you please explain how to answer this: Which of the following is not a plane a) r=(1,3,4)+s(2,-1,2)+t(1,1,1), s,t∈R b) r=(2,4,2)+s(1,-2,3)+t(3,2,2), s,t∈R c) r=(3,2,3)+s(4,-4,2)+t(-2,2,-1), s,t∈R d) r=(-2,1,4)+s(2,2,-1)+t(2,2,1), s,t∈R

*March 17, 2015*

**Vectors**

The shortest distance between a point and a line occurs at: a) infinitely many points b) one unique point c) random points d) a finite number of points

*March 17, 2015*

**Vectors**

Multiple choice. How would I answer this in a short way? what is the distance between the skew lines L1:(0,4,-3)+s(-1,1,3),seR and L2: (1,2,5)+t(-3,2,5),teR? a) 4 root 2 b) 7/2 c) root 2 d) (7 root 2)/2

*March 17, 2015*

**Vectors**

no clue how to answer it. I put each slope into the y=mx+b formula and found the b values, but i'm not sure if i'm supposed to do that

*March 16, 2015*

**Vectors**

Two lines with the slopes m1=4/3 and m2=-7/2 intersect at (3,4). Determine the equations of the two lines and check your answer by solving them

*March 16, 2015*

**Vectors**

would the answer be r-(3,2,-1)+s(1,1,1)

*March 16, 2015*

**Vectors**

Determine the vector equation of a line passing through the point P(3,2,-1) and with a direction vector perpendicular to the line r=(2,-3,4)+s(1,1,-2), seR

*March 16, 2015*

**Calculus**

Determine the slope of the tangent to the function f(x)=5e^x - 2e^(2x) at the point with x-coordinate x=1

*March 16, 2015*

**math**

How would I write the equation y=3.9657(0.9982^x) in the format of g(x)=f(x)+f(x-60)?

*March 14, 2015*

**Calculus**

Find an equation of a line tangent to y = 2sin x whose slope is a maximum value in the interval (0, 2π] I believe the equation is y=2x-4pi. How is the b-value -4pi?

*March 14, 2015*

**Vectors**

Explain why the planes 3x-6y-9z+5=0 and x+2=2y+3z never intersect

*March 14, 2015*

**Vectors**

Does the point of intersection between L1:(4,9,2)+s(1,-1,-1), seR and Ls: (2,11,4)+t(5,-3,-4), teR lie on the plane 3x-2y+3z+4=0?

*March 14, 2015*

**math**

How would I solve this equation for x? 0=3.9657(0.9982^x)ln0.9982

*March 14, 2015*

**Calculus**

How would I find the instantaneous rate of change using this formula y=3.9657(0.9982^x) and given a table of values?

*March 13, 2015*

**Swakop High**

John has $6000 to invest. He invests part of it at 5% and the rest at 8%.How much should be invested at each rate to yield 6% on the total amount?

*March 13, 2015*

**Vectors**

would it be d?

*March 11, 2015*

**Vectors**

which is not a possible type of intersection between three planes? a) intersection at a point b) three coincident planes c) intersection along a line d) intersection along a line segment I know that planes can intersect in a line but I don't know which of c and d would be ...

*March 11, 2015*

**Math**

Explain how the order of operations determines how you simplify a numeric expression. explain the rules for addition, subtraction, multiplication, division, and the use of grouping symbols.

*March 10, 2015*

**College Algebra**

John invested his savings in two investment funds. The $12,000 that he invested in Fund A returned a 3% profit. The amount that he invested in Fund B returned a 10% profit. How much did he invest in Fund B, if both funds together returned a 6% profit?

*March 10, 2015*

**Vectors**

Also, R(-9,18) lies on the line

*March 9, 2015*

**Vectors**

How would you write a vector equation for a line using parametric equations? For example: A line is defined by x=-2-t and y=4+2t,teR. a) Write a vector equation for this line using parametric equations. b) write a second vector equation different from the first

*March 9, 2015*

**Calculus**

For the question "Determine the equation of the tangent to the curve y = xtanx at the point with x-coordinate π." how is the answer -πx + y + π2 = 0?

*March 9, 2015*

**calc**

At noon, ship A is 150 km west of ship B. Ship A is sailing east at 35 km/h and ship B is sailing north at 30 km/h. How fast is the distance between the ships changing at 4:00 PM?

*March 9, 2015*

**chemistry**

Monosodium glutamate (MSG), a food-flavor enhancer, has been blamed for “Chinese Restaurant Syndrome,” the symptoms of which are headaches & chest pains. MSG has the following composition by mass: 35.51 percent C, 4.77 percent H, 37.85 percent O, 8.29 percent N, & 13...

*March 6, 2015*

**Chemistry**

Monosodium glutamate (MSG), a food-flavor enhancer, has been blamed for “Chinese Restaurant Syndrome,” the symptoms of which are headaches & chest pains. MSG has the following composition by mass: 35.51 percent C, 4.77 percent H, 37.85 percent O, 8.29 percent N, & 13...

*March 6, 2015*

**History**

the 2nd one

*March 4, 2015*

**History**

Which best describes a similarity between the outcomes of the French and American revolutions? They brought about a return to absolute monarchy in both countries. They changed the world's ideas about how nations should be ruled. Both countries embraced democracy and set up...

*March 4, 2015*

**History**

Which action by the National Assembly was inspired by Enlightenment ideals and the American Revolution? It added a Bill of Rights to the French constitution. It issued the Declaration of the Rights of Man. It set up a federal tax system based on income. It banned organized ...

*March 4, 2015*

**English Lit.**

meaning of illustration in a question

*March 2, 2015*

**Algebra II**

3885=10t^3+115t^2+25t+2505 −10t3−115t2−25t+1380=0 −5(t−3)(2t2+29t+92)=0 t−3=0 2t2+29t+92=0 t=3 1992

*March 1, 2015*

**Chemistry**

Looks like 0.046 mol NH4OH. So, I just multiply the moles and liters and then compare the two values? The balanced equation isn't really necessary?

*March 1, 2015*

**Chemistry**

If I have 50.0 mL of HA at a concentration of 1.20M and 50.0 mL of NH4OH at a concentration of 0.92M, how many moles of the limiting reactant are there? I guess I should start with a balanced equation, but I have no idea where to start..

*March 1, 2015*

**Algebra Answer ASAP thx!**

Numer 58- 5m6 -------=1.6 3n 5m63n1.6

*February 28, 2015*

**Math**

Find the intersection of the sets A = {3, 4, 7, 9, 13} and B = {3, 7, 10, 13, 17}. null set {3, 7, 13} {3, 4, 7, 9, 10, 17} {3, 4, 7, 9, 10, 13, 17}--- my answer Question 3.3. Choose the correct answer. Find the union of the two sets A = {4, 8, 10, 12, 14} and B = {12, 14}. {...

*February 26, 2015*

**math**

let V be the set of all real-valued continuous functions defined on R1. If f and g are in V, we define f ¨’ g by (f ¨’ g)(t) = f(t) + g(t). If f is in V and c is a scalar, we define c f by (c f)(t) = cf(t). Then V is a vector space, which is denoted by C(&#...

*February 26, 2015*

**math question**

how is this not a subspace of R3? The set of all vectors of the form a b c , where a > 0.

*February 26, 2015*

**History**

Thanks

*February 26, 2015*

**History**

What do we mean when we say the modern world? When did it begin? How is it different from the pre-modern world?

*February 26, 2015*

**Chemistry Pre-AP**

What volume of oxygen gas can be collected at 0.565 atm pressure and 48.0◦C when 42.9g of KClO3 decompose by heating, according to the following equation? 2 KClO3(s) ∆−−−−→2KCl(s) + 3O2(g) MnO2

*February 25, 2015*

**AP Chemistry**

iN A LAB, the orders of two reactants, A and B, were determined experimnetally to be 2 and 3 respectively. a. write the rate law for this reaction. c. what would happen to the rate of the reaction if A were Doubled? d. what would happen to the rate of the reaction if B were ...

*February 24, 2015*

**Life skills**

Why and how someone would prioritize their values?

*February 23, 2015*

**History**

is it the first?

*February 23, 2015*

**History**

Which was not a motivation for European exploration in the fifteenth and sixteenth centuries? the Muslim invasion of Spain the desire to find a sea route to Asia-} my answer the promise of riches intellectual curiosity

*February 23, 2015*

**art**

where is the negative space in the rubin case?

*February 23, 2015*

**Chemistry**

Using household bleach and saltwater of the same molarity, describe the quantities of each that would me needed to make 30 ml of a solution that contained 50% of the hypochlorite in household bleach.

*February 22, 2015*

**statistics**

Estimate the multiple linear regression equation relating number of cups of coffee per week, female sex, and number of hours of exercise per week, considered simultaneously, to GPA. Consider GPA the dependent, or outcome variable. my answer: GPA= 7.301 -1.649 (female sex) -0....

*February 20, 2015*

**Calculus**

also, how is y=2x? did you use y=mx+b? which numbers did you substitute?

*February 17, 2015*

**Calculus**

because f'(0)=2cos(0)=2?

*February 17, 2015*

**Calculus**

how is the slope of 2sinx=2?

*February 17, 2015*

**Calculus**

i found the derivative to be y'=2cosx but i don't know what to do next

*February 17, 2015*

**Calculus**

Find an equation of a line tangent to y = 2sin x whose slope is a maximum value in the interval (0, 2π]

*February 17, 2015*

**Calculus**

Thanks!

*February 15, 2015*

**Calculus**

determine the absolute extreme values of the function f(x)=sinx-cosx+6 on the interval 0<=x<=2pi. This is what i did: 1.) i found the derivative of the function which is f'(x)=cosx+sinx 2.) I set f'(x)=0 and got sinx/cosx=-1 which is tanx=-1 and then x=3π/4...

*February 15, 2015*

**Calculus**

Can someone please explain how to solve this type of question? Determine the maximum and minimum value of the function f(x)=3x3^x - 1

*February 14, 2015*

**Calculus**

ok thanks! Also, how did you simplify it to (7^x)(x^6) (7 + x ln7) ?

*February 14, 2015*

**Calculus**

would the derivative of f(x)=(7^x)(x^7) be f'(x)=(7^x ln7) (7x^6)?

*February 14, 2015*

**Calculus**

Ah i see thanks!

*February 14, 2015*

**Calculus**

a certain radioactive substance is decaying so that at time t, measured in years, the amount of the substance, in grams, is given by the function f(t)=3e^-3t. What is the rate of decay of the substance after half a year: I first found the derivative of f(t)=3e^-3t which is f&#...

*February 14, 2015*

**Calculus**

How would I answer this question? Differentiate the function f(x)=sqrt(cosxsinx)

*February 13, 2015*

**Calculus**

1.)sorry i meant to put x not z. so 9x. 3.)yes it is a stair case exponent

*February 13, 2015*

**Calculus**

1. is the derivative of the function f(x)=5e^(4x-9z) f'(x)= -25e^(4x-9z)? 2. Is the derivative of the function f(x)=e^(2x)-e^(-2x) f'(x)=2e^(2x)+2e^(-2x)? 3. If f(x)=e^-x^-1, would f'(2)=-1/4e^(1/4)?

*February 13, 2015*

**Calculus help and please check answer for a)**

thanks!

*February 13, 2015*

**Calculus help and please check answer for a)**

The decay of a certain substance is modeled by the function N(t)=100(3+e^(-t/3), where the number of particles is represented by N in a time of t hours. a) what is the initial number of particles? - I set t as 0 and got an answer of 400 particles initially b) determine the ...

*February 13, 2015*

**math calculus**

Oh I wrote the question incorrect. It's not to find the difference but to explain the difference between the two functions

*February 13, 2015*

**math calculus**

Oh ok! so 2^x is the inverse of (1/2)^x

*February 13, 2015*

**math calculus**

what is the difference between the function 2^x and (1/2)^x?

*February 13, 2015*

**calculus- min value of function**

thanks!

*February 13, 2015*

**calculus- min value of function**

The answer is -1/2 but how? Which of the following is the minimum value of the function f(x)= sinxcosx? a) 0 b) -1/2 c) -1 d) does not exist

*February 13, 2015*

**core values**

I need some example of personal core values?

*February 13, 2015*

**Calculus**

when I drew a curve through the scatter plot, i did get an exponential decay model. would that be all I would need for the justification part?

*February 13, 2015*

**Calculus**

I am not too sure if I did this question correct. Thanks in advanced! Data table: Time after Consumption (min): 30 60 90 120 150 180 Amount of Codeine in Blood (mg): 27.0 23.5 21.2 18.7 16.6 14.5 1.) create a scatter plot of the data and determine a suitable equation to model ...

*February 13, 2015*

**Calculus**

I am not too sure if I did this question correct. Thanks in advanced! Data table: Time after Consumption (min): 30 60 90 120 150 180 Amount of Codeine in Blood (mg): 27.0 23.5 21.2 18.7 16.6 14.5 1.) create a scatter plot of the data and determine a suitable equation to model ...

*February 12, 2015*

**science**

what is true about red blood cells

*February 11, 2015*

**Math**

Place grouping symbols in the expression so that it has a value of 22. 3 • 4 – 2 + 5 + 7 3 • [4 – (2 + 5) + 7] (3 • 4) – [2 + (5 + 7)] [(3 • 4) – 2] + (5 + 7) 3 • (4 – 2) + (5 + 7)

*February 10, 2015*

**Chemistry**

Upon decomposition, one sample of magnesium fluoride produced 1.55 kg of Magnesium and 2.42 kg of fluoride. A second sample produced 1.10kg of magnesium. How much fluoride (in grams) did the second sample produced?

*February 5, 2015*

**Math**

formalize the following statment: a_n is a sequence that doesnt converge to L∈R. prove that the sequance (1/n) does not converge to 1. Can someone please explain to me what i have to do in the question i do not understand it so well.

*February 2, 2015*

**math**

A video game Is On sale For 30% Off The rehilarious price Of $50. What Is The sale price Of The video game?

*January 25, 2015*

**home economics**

Please help me!,how is home economics related to mathematics,science and social,spiritual and moral education (ssme)?

*January 24, 2015*

**applied math**

You are wallpapering a 10-foot long wall. The wall is 10 feet high, and without doors and windows. The solid-colored wallpaper you've selected is 30 inches wide and comes in 20-foot rolls. How many widths of paper will it take to cover the wall? How many rolls of wallpaper...

*January 23, 2015*