# Posts by Iris

Total # Posts: 248

**chem 11**

Chloroform, CHCl3, has a boiling point of 62 oC, whereas methane, CH4, has a much lower boiling point of -164 oC. Using diagrams, explain the difference between the two boiling points.

*January 4, 2017*

**Pre-Calculus**

The cost of sending a package overnight is $14.40 for the first pound and $3.90 for each additional pound or portion of a pound. A plastic mailing bag can hold up to 3 pounds. The cost f(x) of sending a package in a plastic mailing bag is given by the following function, where...

*December 12, 2016*

**Pre-Calculus**

Which of the following shows the correct notation for “The limit of x^2 - 1 as x approaches 3. A. lim x^2-1 x->3 B. lim3 x->x^2-1 C. lim(x^2-3) x->x^2-1 D. lim(x^2-1) x->3 Thank you

*December 12, 2016*

**Pre-Calculus**

What is the correct notation for “The limit of x^2 - 1 as x approaches 3? Thank you

*December 12, 2016*

**Pre-Calculus**

How does the expansion of (x + y)n and (x - y)n differ? If you can offer an example that would be very helpful. Thank you

*December 12, 2016*

**Pre-Calculus**

Find P_(k+1) if P_(k)=2^(k-1)/k! (I used _ as a sign for a subscript) A. 2^(k+1)/(k+1)! B. 2^k/(k+1)! C. 2^(k+1)/k!+1 D. 2k/k!+1 Thank you

*December 12, 2016*

**Pre-Calculus**

Which of the following shows the correct first step to prove the following by mathematical induction? 3 + 11 + 19 + 27 + … + (8n - 5) = n(4n - 1) A. 3 + 11 + 19 + 27 + … + (8 • 1 - 5) = 1(4 • 1 - 1) B. 8 • 1 - 5 = 1(4 • 1 - 1) C. 3 + 11 + 19 + 27...

*December 11, 2016*

**Pre-Calculus**

Find P + 1 if Pk = 7 + 13 + 19 + ...+[6(k - 1)+1] + (6k + 1) (the k+1 and k in front of the P are subscripts) A. 7 + 13 + 19 + …+[6(k - 1) + 1] + (6k + 1) + [6(k + 1) + 1] B. 8 + 14 + 20 + …+[7(k - 1) + 1] + (7k + 1) C. 7 + 13 + 19 + …+(6k + 1) D. 7 + 13 + 19...

*December 11, 2016*

**Pre-Calculus**

?*

*December 6, 2016*

**Pre-Calculus**

Can someone please explain how eccentricity can be used to classify conics.

*December 6, 2016*

**Calculus**

Use a graphing utility to graph the polar equation shown below. r = cos 5? + n cos ?, 0 ? ? ? ? For the integers n = -5 to n = 5. As you graph these equations, you should see the graph change shape from a heart to a bell. I'm sorry. I'm having issues with graphing this.

*December 6, 2016*

**English**

How is close reading related to annotation? How are they similar?

*December 5, 2016*

**Pre-Calculus**

Convert to rectangular: 4=4sec theta A. y=2 B. y=4 C. x=2 D. x=4

*December 2, 2016*

**Pre-Calculus**

Convert to rectangular: theta=(2pi)/3 A. y=-sqrt3 B. y=-sqrt3x C. x=sqrt3 D. x=-sqrt3y

*December 2, 2016*

**Pre-Calculus**

Convert to rectangular: theta=2pi/3

*November 30, 2016*

**Pre-Calculus**

Which are examples of the use of parametric equations? A. Position of a person on a ferris wheel. B. Position of a ball after being thrown. C. A and B D. Neither A nor B

*November 30, 2016*

**Pre-Calculus**

Which is the best example of the use of parametric equations? A. Measuring weight on the moon. B. Finding the position of a person in a city. C. Determining the position of a satellite during a specific time of day. D. Finding the right parameters to use for a construction ...

*November 30, 2016*

**Pre-Calculus**

Can you please give and example of a hyperbola and ellipse with the same vertices and center that I can graph? Then explain the similarities and differences between the graphs.

*November 29, 2016*

**Pre-Calculus**

given: ((x-2)^2/9)+((y-4^2/16)=1 what is the major axis?

*November 29, 2016*

**Texas History**

My answer is D

*November 18, 2016*

**Texas History**

Why did Santa Anna attack the Alamo? A. It had a supply of gold. B. It was an important strategic location. C. It was his family’s ancient homeland. D. It would ensure a glorious victory.

*November 18, 2016*

**Calculus**

Which of the following would be the best first step when solving the following system using the substitution method? x - y = -4 ; x + 2y = 5 a. x = -4 - y b. x = -4 + y c. 2y = 5 - x d. 2y = 5 + x

*November 9, 2016*

**Trig**

find the angle between u=7i+2j and v=-4j

*November 9, 2016*

**Calculus**

Given: u <-1, 7> and v <4, -3> What is the measure of the angle between them?

*November 5, 2016*

**Pre-Calculus**

Given: u <-1, 7> and v <4, -3> Find: (u • v)(u + v)

*November 5, 2016*

**Calculus**

Find the dot product of: <-1, 7> and <2, ¾>.

*November 2, 2016*

**Calculus**

What is the unit vector of v: <-6, -8>?

*November 2, 2016*

**Calculus**

Given the vectors u = <−3, 7> and v = <5,1>, find 3u + 2v.

*October 28, 2016*

**Trig**

Given tan(A) = 2 and A is in Quadrant I, find cos(2A). A. 0 B. 1 C. 1/2 D. -3/5

*October 7, 2016*

**Trig**

Just confused. Given tan(A) = 2 and A is in Quadrant I, find sin(2A). A. 0 B. 1 C. 1/2 D. 4/5

*October 7, 2016*

**Pre-Calculus**

Given Tan(A) = 5 in Quadrant III and Sin(B) = ⅔ in Quadrant II, find Cos(A-B).

*October 6, 2016*

**Pre-Calculus**

Given Sin(A) = ⅗ and Cos(B) = 8/17 in Quadrant I, find Sin(A+B).

*October 6, 2016*

**Pre-Calculus**

A.Verify the identity. B.Determine if the identity is true for the given value of x. Explain. [cot(x) – 1] / [cot(x) + 1] = [1 – tan(x)] / [1 + tan(x)], x = π/4 I solved A and I believe it's true; however, I need help with B.

*October 5, 2016*

**Pre-Calculus**

A.Verify the identity. B.Determine if the identity is true for the given value of x. Explain. Sec(x) / tan(x) = tan(x) / [tan(x) – cos(x)],x = π I already solved A and I believe it's true; however, I need help with B.

*October 5, 2016*

**Pre-Calculus**

This question has me stuck. Use the Pythagorean identity sin^2 Θ + cos^2 Θ = 1 to derive the other Pythagorean identities, 1 + tan^2 Θ = sec^2 Θ and 1 + cot^2 Θ = csc^2 Θ. Discuss how to remember these identities and other fundamental identities.

*September 29, 2016*

**History! Help!**

Yea! A. It created large populations

*September 7, 2016*

**History! Help!**

The Caddo were an American Indian group in Texas that practiced agriculture and build permanent houses. What can be inferred about the group? A. It created a large population B.It formed a small and defenseless population C.It had no contact with other groups D.It was nomadic ...

*September 7, 2016*

**History! Help!**

The Atakapans occupied the region from the Sabine river to the A. San Jacinto river B. Red river C. Colorado river D. Trinity river Both the Karankawa and Atakapans relied heavily on which resources? A.rival groups B.fish and shellfish C.settlers D.trees and nuts Both the ...

*September 2, 2016*

**History! Help!**

Is that right?

*September 1, 2016*

**History! Help!**

Well.... it would be A?

*September 1, 2016*

**History! Help!**

Which of the following lists the start of the agricultural revolution according to absolute chronology? A. AD 500 B. after hunting and gathering C. post-Spanish exploration D. 5000 BC

*September 1, 2016*

**Pre-Calculus**

Which of the following statements best describes the domain of the functions sine and arcsin? A)Sine domain is all real numbers; Arcsin domain is all real numbers. B)Sine domain is restricted; Arcsin domain is all real numbers. C)Sine domain is all real numbers; Arcsin domain ...

*August 30, 2016*

**Pre-Calculus**

Use a graphing utility to graph the function y = d + a sin (bx - c) for different values of a, b, c, and d. Write a paragraph describing the changes in the graph corresponding to changes in each constant.

*August 14, 2016*

**Pre-Calculus**

You are given the value of tan Θ. is it possible to find the value of sec Θ without finding the measure of Θ? Explain.

*August 12, 2016*

**Math**

125

*May 3, 2016*

**Math**

opps i ment to put 1/2 sometimes it dosent work

*May 3, 2016*

**Math**

You read 50 pages in an hour. Your sister reads 40 pages in an hour. Explain how to find out how many more pages you read than your sister reads in 1212 hour?

*May 3, 2016*

**Social Studies**

The correct answer is B, abolish slavery by ratifying the thirteenth amendment and condemn the act of secession.

*April 15, 2016*

**health**

Trinity is correct, and 16 is B. Thanks Jake and Trinity. :)

*March 8, 2016*

**science !!**

The first one is D and the second one is B. Just took this, got 100%

*March 3, 2016*

**college algebra2**

a triangle whose base is 18 inches long has an area of 280 square inches. find the area of a similar triangle whose base is 6 1/4 feet long.

*February 12, 2016*

**Science**

Yes, the correct answer is definitely B, high altitude.

*January 28, 2016*

**Social Studies Help**

opps 1.A 2.B 3.C 4.A 5.D 6.B

*December 15, 2015*

**Social Studies Help**

1.A 2.B 3.C 4.A 5.A 6.D 7.B

*December 15, 2015*

**Social Studies Help**

The social unit most responsible for teaching the custom and traditions of a culture is? (A) The family (B) The government (C) The army (D) The schools Two important features of a culture are? (A) Weather and writing (B) Language (C) Economy and Climate (D) Natural resources ...

*December 15, 2015*

**Math**

I had chose B but i am not entirely sure

*December 8, 2015*

**Math**

Which number is equivalent to 14/4? A 3.2 , because 14 divided by 4 is 3 with a remainder of 2 B 3.5 because 14 divided by 4 is 3 with a remainder of 2 and 2/4 = 0.5 C 3.3 because 14 divided by 4 is 3 with a remainder of 3 D 3.6 because 14 divided by 4 is 3 with a remainder of...

*December 8, 2015*

**Science**

The answer is color.

*November 29, 2015*

**Health**

Thanks all! D False A 100%

*November 17, 2015*

**Science please help :)?**

Yes, those are the correct answers.

*October 21, 2015*

**Shalee ^~^**

Thanks bruh, you are correct. B C B A 100%

*October 7, 2015*

**Science**

The answers are: 4. A 12. B 15. C 16. B 17. C 19. A Trust me, 100%

*October 6, 2015*

**Math**

Hayden had 2 1/2 gallons of water in his watering can. The seed packet said to use 1/4 of a gallon for peppers and 5/8 of a gallon for tomatoes. Hayden then used some of the water for lettuce. If Hayden had 3/4 gallons of water left over, about how much water did he use for ...

*September 28, 2015*

**Science**

How can you evaluate scientific claims? NEED HELP!

*September 18, 2015*

**Science**

how can models help in science, why they are important, what and some examples of models.

*September 18, 2015*

**Math**

1/16

*September 18, 2015*

**Physics**

An 83-kg fireman slides down a fire pole. He holds the pole, which exerts 500-N steady resistive force on the fireman. At the bottom he slows to a stop in 0.49 m by bending his knees. Determine the acceleration of the fireman while sliding down the pole.

*September 14, 2015*

**Art**

Do all art paintings have culture in the paintings

*August 31, 2015*

**Science**

that is better Thxs That really helps me

*August 29, 2015*

**Science**

the model at UTPA

*August 29, 2015*

**Science**

Need some help? How is the model of King Tut like other models used by scientists?

*August 29, 2015*

**LA**

what is the difference between internal conflict and external conflict Need help A.S.A.P

*June 15, 2015*

**6th Grade Math :(**

welcome

*June 10, 2015*

**6th Grade Math :(**

about 4 hours

*June 10, 2015*

**Math**

oh ok i get it now

*June 10, 2015*

**Math**

i do not understand if it is 6% then is this explanation how you got 12%. which is it 6% or 12%

*June 10, 2015*

**Social Studies**

ok i will do it on my own good night

*June 4, 2015*

**Social Studies**

kk

*June 4, 2015*

**Social Studies**

ok srry my original question is Why did most major northeastern cities in the United States develop along the coast? and it does have why in the beggining

*June 4, 2015*

**Social Studies**

but i still do not get what reed means he says "The answer to "why" is "yes"

*June 4, 2015*

**Social Studies**

oh yeah

*June 4, 2015*

**Social Studies**

i do not get you reed

*June 4, 2015*

**Social Studies**

yes

*June 4, 2015*

**Social Studies**

is that right

*June 4, 2015*

**Social Studies**

ships

*June 4, 2015*

**Social Studies**

Why did most major northeastern cities in the United States develop along the coast?

*June 4, 2015*

**Social Studies**

:)

*June 4, 2015*

**Social Studies**

iris

*June 4, 2015*

**Social Studies**

i know you all might be mad but i need help again here is the question What region of the United States did the first settlers arrive

*June 4, 2015*

**language arts**

i agree it is awesome but the ending i was just made

*June 4, 2015*

**Social Studies**

oh ok i get it

*June 4, 2015*

**Social Studies**

now is that right reed

*June 4, 2015*

**Social Studies**

that the expansion of the US throughout the American continents

*June 4, 2015*

**Social Studies**

is that right reed

*June 4, 2015*

**Social Studies**

the belief or doctrine, held chiefly in the middle and latter part of the 19th century

*June 4, 2015*

**Social Studies**

opps srry wrong name United States that American settlers were destined

*June 4, 2015*

**Social Studies**

the belief or doctrine

*June 4, 2015*

**Social Studies**

well this is what i got the americans traveled to the west and settled does that sound right

*June 4, 2015*

**Social Studies**

oh well that was not me

*June 4, 2015*