# Posts by lindsay

Total # Posts: 620

**Chemistry**

In the synthesis of asprin we react salicylic acid (HOOCC6H4OH) with acetic anhydride (C4H6O3) . The unbalanced chemical equation is: HOOCC6H4OH + C4H6O3 --> HOOCC6H4O2C2H3 + H2O If we mix together 28.2 g of salicylic acids with 15.6 g of acetic anhydride in this reaction ...

**Math**

Find the value of x if line QS bisects angle PQR and measure of angle PQR equals 82 degrees. angle PQS=10x+1

**Geometry**

Find the point, M, that divides segment AB into a ratio of 3:2 if A is at (0, 15) and B is at (20, 0).

**Stastics**

Which of the following descriptions of confidence intervals is correct? (Select all that apply) a. If a 95% confidence interval contains 0, then the 99% confidence interval contains 0 b. If a 99% confidence interval contains 0, then the 95% confidence interval contains 0 c. If...

**stastics**

The value of “t” will increase as the standard deviation of the difference _____ and the difference between means ____. a. increase; decreases b. increases; increases c. decreases; decreases d. decreases; increases e. None of the above. Wouldn't this answer be ...

**Stastics**

Can someone help me and let me know if what I have solved is correct. A researcher randomly surveyed 300 high school seniors and determined 225 stated they drive a car to high school. We are interested in the population proportion of seniors who drive a car to high school. a. ...

**Math**

These marbles are placed in a bag and two of them are randomly drawn. What is the probability of drawing 2 pink marbles if the first one is placed back in the bag before the second draw? There are 3 pinks, 2 yellows, and 5 blues.

**math**

these marbles are placed in a bag and two of them are randomly drawn what is the probability of drawing two pink marbles if the first one is placed back in the bag before the second draw the bag has 10 marbles.2 yellow.3 pink.5 blue

**math**

these marbles are placed in a bag and two of them are randomly drawn what is the probability of drawing two pink marbles if the first one is placed back in the bag before the second draw thebag has 10 marbles.2 yellow.3 pink.5 blue

**Mathmatics**

I want to be able to have $50,000 a year during retirement. I want to make sure that I can have it until I am 100 years old. I plan to retire at 65. I can earn 6%. How much do I need to have at retirement to be able to make it?

**math**

solve the equation 6y-2=8y-5

**algebra**

7.2-8.6+(9.3)-(-5.4)

**calculus**

Simplify the following power functions to the form y=kxp, where k and p are some numbers. (a) y=(18)/x√ is y=kxp. What are k and p?

**Physics II**

A large cylindrical water tank 11.5 m in diameter and 13.5 m tall is supported 8.75 m above the ground by a stand. The water level in the tank is 10.6 m deep. The density of the water in the tank is 1.00 g/cm3. A very small hole is formed at the base of the vertical wall of ...

**English**

Would lonely or isolated be considered character trait

**English**

What character traits can be made out of this? "He was a gentlemen from sole to crown, Clean favored, and imperially slim." "And he was always quietly arrayed." And he was rich - yes, richer than a king- And admirably schooled in every grace:" I don&#...

**English**

What character trait is seen in "Richard Cory" when it says "But still he fluttered pulses when he said, "Good-morning," and he glittered when he walked."

**English**

What are the character traits for Richard Cory in the poem "Richard Cory"? What is the mood in "Richard Cory"? What qualities does he possess that makes him memorable?

**calculus**

This answer is still incorrect. The 3 miles from the airplane to the kangaroo is the hypotenuse of the triangle. It is the shortest distance from the airplane to the kangaroo, not the horizontal distance.

**math**

Show that 4/2^x = 2^2-x and hence or otherwise solve for x in the equation 2^x +2^x-2 =5

**math**

27 root 3 =3^b. Find the value of b.

**physics**

The electron in a certain hydrogen atom has an angular momentum of 6.834 × 10-34 J·s. What is the largest possible magnitude for the z component of the angular momentum of this electron? For accuracy, use h = 6.626 × 10-34 J·s. I know you need to use ...

**math**

An A.P. is given by k,2k/3,k/3, 0,... Find the 6th term.

**algebra**

Find 1. the binomial expansion of (3+2x)^5 simplifying terms. Hence find the binomial expansion of (3+2x)^5 +(3-2x)^5.

**algebra**

Find 1.The first 4 terms of the binomial expansion in ascending powers of x of (1+x/4)^8. 2.Use your expansion to estimate (1.025)^8

**math**

Find the first three terms in ascending power of 'x' of the binomial expression of (3+bx)^5 where b is a non zero constant.

**math**

A series is defined by 8+4+2+1+1/2+1/4+...+1/32 Write the series in sigma notation

**math**

find the sum of an A.P.of eleven terms whose first term is 1 and whose last term is 6.

**math**

The sum of the first 20 terms of an arithmetic series is identical to the sum of the first 22 terms. If the common difference is -2, find the first term.

**math**

a 40 year building programme for new houses began in 1951(year 1) and finished in 1990 year (40). The number of houses built each year form an A.P. With the first term 'a' and the common difference 'd'. Given that 2400 new houses were built in 1960 and 600 new ...

**math**

Given that 2 log base2 (x+15) - log base2 x = 6 1.Show that x^2 -34x +225 = 0 2. Hence or otherwise solve the equation 2 log base 2 (x+15) - log base 2 x =6

**math**

Solve 4^y -7(2^y) = 8

**math**

Solve 3 log x = 1 + log (4x+5)/ log 2

**math**

Given that x = 2log t is a solution of the equation10^(2x+1) -7(10^x) -26 =0. Find t

**physics**

The drawing shows an equilateral triangle, each side of which has a length of 4.53 cm. Point charges are fixed to each corner, as shown. The 4.00 C charge experiences a net force due to the charges qA and qB. This net force points vertically downward and has a magnitude of 779...

**maths**

How did you arrive at 10^2?

**maths**

Solve log(5x-1) = 2 + log(x-2)

**maths**

Given that x=lg a is a solution of the equation 10^(2x+1)-7(10^x) =26. Find the value of a.

**math**

solve the equation for x. 3^2x - 3^x+2 +8 =0 Ps. The topic is logarithmic and exponential functions

**geometry**

A floor measures 10m by 5m is to be covered with flooring boards measuring 1m 20cm. How many flooring boards would be needed to cover this section.

**Stats.**

Okay, never mind I think I got this one....

**Stats.**

Another one that I need help.... At Ajax Spring Water, a half-liter bottle of soft drink is supposed to contain a mean of 520 ml. The filling process follows a normal distribution with a known process standard deviation of 4 ml. (a) Which sampling distribution would you use if...

**Stats.**

I don't know where to begin with this one.... When told that over a 10-year period a mammogram test has a false positive rate of 50 percent, Bob said "That means that about half the women tested actually have no cancer". Correct Bob's mistaken interpretation.

**Physics/ Chem**

Find the entropy change when 51g of steam condenses to water at 100 ∘C.

**Physics**

A cylinder with a movable piston encloses 0.39 mole of ideal gas at 308K . How much heat is required to increase its volume isothermally by a factor of 3? 1100J 1400J 1600J 550J

**Statistics**

Daily output of Marathon's Grayville, LA, Refinery is normally Distributed with a mean of 232,000 barrels of crude oil per day with a standard deviation of 7,000 barrels. a. what is the probability of producing at least 232,000 barrels? b. between 232,000 and 239,000 ...

**Stats.**

how do I use it?

**Science**

Natural selection.

**math**

Solve this equation for x Log3^2x+5 =1

**Science**

CAN SOMEONE HELP WITH MY HOMEWORK?

**math**

0.06 2/3 into a fraction

**Calculus**

The total stopping distance T of a vehicle is T=2.5x+0.5x^2 where T is in feet and x is the speed in miles per hour. Approximate the change and percent change in total stopping distance as sped changes from x=25 to x=26 miles per hour. I started taking the derivative, but that...

**Calculus (check my work)**

You realize I'm a terrible Calculus student? I don't understand the concepts that the other students can pick up on right away. I don't really get why you did any of what you did, and there aren't any examples like this one in our book for me to look back on.

**Calculus (check my work)**

Okay, I really don't understand how you did any of that. What's the point of half of it? I tried to do some of what you did, but I got different numbers for my answers.

**Calculus (check my work)**

Also, it says to estimate the maximum allowable percent error in measuring the circumference if the error in computing the area cannot exceed 3%. How do I do this?

**Calculus (check my work)**

The measurement of the circumference of a circle is found to be 64 centimeters, with a possible error of 0.9 centimeter. Approximate the percent error in computing the area of the circle. MY ANSWER 8.83%

**Calculus (check my answer)**

No, this is a different part of that same problem. It asks for the surface area this time, not volume.

**Calculus (check my answer)**

The measurement of the edge of a cube is found to be 15 inches, with a possible error of 0.03 inch. Use differentials to approximate the maximum possible propagated error in computing the surface area of the cube. I got 5.4 inches squared. Is this right?

**Calculus (check my answers)**

Thank you soooo much!

**Calculus (check my answers)**

Never mind number 20! Someone already helped me with it!

**Calculus (check my answers)**

10) Use the information to evaluate and compare delta y and dy. y=2-x^4, x=2 and delta x=dx=0.01 MY ANSWER: dy=-.32 and delta y=-.3224. Are they supposed to be negative, and how do I compare those in words? I don't even understand what I was supposed to do... 12) Find the ...

**Calculus**

Hold on...I think I just managed to kind of figure it out!

**Calculus**

Wait, I'm not understanding how you get the tanx -x part...

**Calculus**

Find the differential dy of the given function. y=sec^2x/(x^2+1) My answer was [tanx(x^2+1)-2sec^2x]dx/(x^2+1)^2 My friend (who's a lot smarter than me) got something wayyy different, so I'm not sure if I'm doing this wrong...?

**Calculus**

Consider the function x^2+x-4 Estimate the area between the graph and the x-axis between x=2 and x=4 using four rectangles and right end points.

**Calculus**

The measurements of the base and altitude of a triangle are found to be 36 and 50 centimeters, respectively. The possible error in each measurement is 0.25 centimeter. Use differentials to approximate the possible propagated error in computing the area of the triangle.

**Calculus**

Please, don't assume that we've been taught this stuff because we were literally just handed a packet and told to learn it ourselves. I don't understand this in the slightest. The question is: Use the information to evaluate and compare delta y and dy. y=2-x^4, x=2...

**Calculus**

Wait, never mind. I'm overthinking it and I made a dumb mistake. Disregard these two answers.

**Calculus**

Hold on; I think I did delta y wrong. If you set it up like that, then you would get 2-(4.01)^4 -2+2^4. And you get a ridiculous number...?

**Calculus**

Please, don't assume that we've been taught this stuff because we were literally just handed a packet and told to learn it ourselves. I don't understand this in the slightest. The question is: Use the information to evaluate and compare delta y and dy. y=2-x^4, x=2...

**math**

Solve /3x + 12/ >= 21 PS>= means is greater than or equal to.

**Calculus**

I know that; don't know why I didn't use it. Oops. How do you get 0 from f(x)?

**Calculus**

Use the information to evaluate and compare (triangle)x and dy. y=2-x^4, x=2, and (triangle)x=dx=0.01

**math**

Factorize b^4-16 PS. "b" is really the letter b

**math**

Solve 16(4^2x-1)= 8^x+3

**math**

Change 1010101011 base 2 to base 4

**math**

If 203n + 2m4n = 501n. a. Find the value of base n. b. Find the value of m PS the 'n' is really base n.

**math**

f(x) =x-2/x-3. I calculated f^-1 (x)to be 3x-2/y-1. How do I use f^-1 (x) to evaluate (x-2/x-3)=4. P.S/ f^-1 means 'f' inverse.

**Calculus (Please check my work.)**

Also, for 5, is the marginal cost at 31 $186?

**Calculus (Please check my work.)**

Thanks so much for pointing those things out! But I do have a question on #2? How'd you get the 6 for the maximum profit? I got the equation -4x^2+48x-18, but I couldn't get the 6. (It's probably some really stupid mistake. I make a lot of those. hahaha)

**Calculus (Please check my work.)**

This is my last chance to make at least a C in my AP Calculus course, so please tell me if I got these right or wrong so that I can fix them before it's due. Also, there was one I wasn't sure how to do, so if you can help me with that, it would be much appreciated! 1)...

**Calculus**

How do you show that the minimum average cost occurs when the average cost equals the marginal cost?

**math**

Solve (x^3 y)^2/8x^1/3

**math**

solve the following inequality /3x + 12/ >/ 21 PS >/ means greater than or equal to.

**Calculus PLEASE HELP**

Show that the maximum profit occurs when the marginal revenue equals the marginal cost. I'm pretty sure this is supposed to be some sort of proof, but I have no idea how to even start it...

**Calculus**

Show that the maximum profit occurs when the marginal revenue equals the marginal cost. I'm pretty sure this is supposed to be some sort of proof, but I have no idea how to even start it...

**math**

What is the negation of p and q?

**math**

solve the following absolute value question /4x + 5/ =25

**math**

The equation kx^2 -2x-7=0 has two real and identical roots, find the value of k.

**maths**

The following statement defines a relation R in the natural numbers N. state whether or not each relation is symmetric 1. x is less than or equal to y 2. x+y =10

**Calculus**

Never mind, I got it!

**Calculus**

Y=5x^4 -24x^3+24x^2+17 is concave down for which interval? A) x<0 B) x>0 C) x<-2 or x>-2/5 D) x<2/5 or x>2 E) 2/5 < x < 2 I know you take the second derivative...but I keep getting stuck with something that won't factor right?

**Calculus**

If x^2=25-y^2, what is the value of [(d^2)(y)]/(dx^2) at the point (3,4)?

**Math**

Okay, well, I don't know how the tracher's getting her answers then.,.

**Math**

Factor 5x^2 -6x-4 I must be having an off day or something; this can factor, right!?

**Calculus PLEASE HELP**

Given that C(x)=2x^3-21x^2+36x+1000 is a cost function, determine the intervals for which the cost is increasing. Determine any intervals for which the marginal cost is increasing. Marginal cost is when you derive the cost function, correct? So do you do the second derivative ...

**Calculus**

Given that C(x)=2x^3-21x^2+36x+1000 is a cost function, determine the intervals for which the cost is increasing. Determine any intervals for which the marginal cost is increasing. Marginal cost is when you derive the cost function, correct? So do you do the second derivative ...

**Calculus**

Using the equations R(x)=-x^2+400x and C(x)=x^2+40x+100, find the Maximum Revenue

**Calculus (check my work)**

Yes! Thank you! I do have another question, though. The second part of the problem says to "compare R(11) -R(10) with that result." Does that mean that I derive it before plugging in 11 and 10 or...?

**Calculus (check my work)**

Find the marginal revenue at x=10 using the equation R(x)=-x^2+80x Is the answer 60?