4,691 results

### For Reiny

If you could go back and check my reply to you. thanks

RE: (- sin (x/2) /( 2 sin (x/2) + cos (x/2)) is an alternate representation for, 1 / ( 4 tan (x/2) + 2 ) Thanks for your help, sorry I posted 3 times, I thought you didn't understand what I needed. I really do appreciate your time spent. just for your FYI, if you are ...

### Reiny+Damon

Can you reply to my last math+log post =) thanks. I'm going to be having alot of math questions today.

### trig

Reiny 2+1/3*tan(theta)=2 How do you get 0? Thanks for your help.

Hey there, just need help with these two. I need someone to help explain them to me/break them down. 1. gr 1/100=_____mg Answer: 0.6 2. 0.3mg= gr_____ Answer: 1/200 3. gr iii /ss= ______mg Answer: 210 Thank you in advance! *** REPLY: I did not get these answers. These are the ...

### Trig

#1 (1/sinx)(sin^2x + cos^2x(sinx/cosx) )/(sinx + cosx) = (sinx + cosx)/(sinx+cosx) = 1 Reiny helped with this question but I don't how Reiny did it. Please explain

### To Reiny

Reiny could you please check my Calculus post below, it says Calculus--Reiny.

### trig

Solve without using a calculator or tables cos(5pi/6 + pi/4) Thank you Reiny!:)

### trig

Solve the given triginometric equation analytically 7 sinx - 2 = 3(2 - sin x) If your are online, thank you my dear Reiny:) Priya

### Math (Reiny??)

Mrs. Reiny ... As in Harris County Mrs. Reiny?

### Reiny+ In need of help

Hey Reiny, could you please take a look at my expo growth and decay post? Thanks alot.

### math (final trig problem)

Solve for x on the interval [0,π/2): cos^3(2x) + 3cos^2(2x) + 3cos(2x) = 4 I havent done trig for a while so what exactly does that mean in solving for x on that interval and how would i go about doing that? Where are you getting these tough trig questions?? how about ...

### Reiny

Reiny I think I have found out the rectangle problem. Could you check and see if Ive got it correct?

### Reiny! Reiny! Reiny!

1. Oanh walked from her home to the grocery store at 3 mi/h and jogged home at 6 mi/h. Her total round trip was 15 minutes (1/4h). How far from Oanh's home is the grocery store? (use an equation to solve this) Help, I am totally clueless on this.

can someone reply to my last chem post

Can someone reply to my previous post.

### trig

Solve the given triginometric equation analytically. Use values of x for 0 less than or equal to x less than 2pi P.S Thanks Reiny for your last post, if you are still online.

### reiny

reiny why are you so smart thanks for aswering my question

### drwls, or other tutors

does my last postage seem correct for the answers that i got. The one that doesn't have a reply. See previous reply to your post.

### Trig.......

I need to prove that the following is true. Thanks (2tanx /1-tan^x)+(1/2cos^2x-1)= (cosx+sinx)/(cosx - sinx) and thanks ........... check your typing. I tried 30º, the two sides are not equal, they differ by 1 oh , thank you Mr Reiny I'll tell my teacher this Question is ...

### reiny

How do I find a variance for a set of numbers {1,16,8,17,12} I got that variance-34.2, but I'm unsure. Any help? Thanks. math - Reiny, Sunday, January 24, 2010 at 8:16pm look at his page. Reiny - April, Sunday, January 24, 2010 at 8:25pm I looked at that page and did my ...

### sir steve help me reiny reiny

2) A quality of identical plastic books weigh 10.98kg ,if each book weighs 54.9g .How many books are there

### TO REINY

Hi reiny i just wanna say thank you for always answering my questions thanks for always helping me <3 thank you may god bless you

### Jiskha

Jiskha homework help rocks. But I need someone to reply to my post: social studies!!!! -afton PLEASE REPLY!!!!!!!!!!! 10/9 - 9:21 pm

### reiny

thanks reiny--but i'm in 6th gr and we r not studying powers..can you help me with a simpler answer without powers?

### Calculus--Reiny

Calculus - Reiny, Friday, December 23, 2011 at 6:59pm I read that as (4a^2-1)/(4a^2-16) * (2-a)/(2a-1) , my brackets are necessary = (2a+1)(2a-1)/( 4(a+2)(a-2) * (2-a)/(2a-1) the (2-a)/(a-2) are opposite, they will give you the -1 so.. = -(2a+1)/(4(a+2)) , again you have to ...

### series maths steve reiny bob reiny steve!!!

if p is the nth term 8+20+52+.....+p evaluate the sum to n-of the series plz show step

Hi Reiny, I posted this problem earlier and you responded but I don't get the reasoning- The problem was -2log8(x+1) = -8 you said multiply by -2 and then you put log8(x+1)=4(wasn't that dividing by -2) log8(x+1)^2 = 8 (how did you get to the power of 2 and =4 became =8 x+1 = ...

### TRIG!

Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6 x=1 - (3/4)sin^2 2x work on one side only! Responses Trig please help! - Reiny, Monday, February 23, 2009 at 4:27pm LS looks like the sum of cubes sin^6 x + cos^6 x = (sin^2x)^3 + (cos^2x)^3 = (sin^2x+cos...

### Urgent math question for Reiny

Find the value of the expression below for r=4 and t=2.... t^3-r+20 divided by r 9*** 72 6 40 Ok, Reiny you said my answer9 was originally wrong, however when I looked at the work you did and you put in parenthesis()....my question is why, because the original expression didn'...

### to reiny

Reiny i got (x+5)(x-3) x=-5 or x=3

Thanks Reiny!

### English

I am writing a letter, in the closing I wrote, If you reply by [a date].... or If you reply back by [a date].... Is the "back" necessary?

### Pre-Calculus - Reiny

Reiny you helped me with this logarithm yesterday: How did you write it out as log2 ( √A / B^3 ) Laws of logarithms combine, write as a single logarithm Need help on this question please, Im stuck, don't know where to go abouts from here: I did it on paint and uploaded ...

### URGENT~MATH For Steve or Reiny

For questions 5-7, find the solution to the system of equations by using either graphing or substitution. 5)y=6-x and y=x-2 (1point) (2,4) (-4,2) (4,2) no solutions 6)y=2x-1 and y=x+3 (1point) (4,7) (7,4) (-7,-4) no solutions 7) y=4x and y+x=5 (1point) (-4,1) (1,4) (-3,2) (2,3...

### Maths - Reiny

Show that the equation 3x^2 - x^3 + 3 = 0 can be rearranged to give: x = 3 + 3 ---- x^2 x^3 = Divide by ? = x = 3 + 3 ---- x^2 Using Xn+1 = 3 + 3 with x0 = 3.2 ---- x^2n find the values of x1 x2 and x3? What to the values of x1 x2 and x3 represent? The represent estimates of a...

### maths steve reiny bob reiny!!! Help

If line 2x+y=-3 and x-2y=1 form the sides of a rectangle whose other sides meet at the point (3, 4), find the equations of the other sides and the area of the rectangle plz help show solution step

### TO REINY

Thank you Reiny, Why I have to divide 632/1.05? I was dividing 632/0.05, I need to understand for future similar problems, I really appreciate your help, I finished school almost 30 years ago, I decided to go back to school an obtain a degree, I try my best but so many years ...

### hello reiny damon steve can you help me physics

Find the Gravitational potential at a point on the earth's surface. Take mass of earth as 5.98*10^24kg, it's radius as 6.38*10^6m and G=6.67*10^-11Nm^2kg^-2. Plz i need sir damon and steve including reiny to show me step and solution plz

### Calc I (@Reiny)

y = x^3 - 8x^2 + 6x -2 has a slope of 6 at two points, what are the coordinates? I used Reiny's way to help solve this answer. Please check if I've done it correct: y'= 3x^2-16x+6 3x^2-16x+6=6 3x^2-16x=0 x(3x-16)=0 Solve for x's x=0 3x-16=0 ~> x=16/3 Plug x values to ...

### Calc I (@Reiny)

y = x^3 - 8x^2 + 6x -2 has a slope of 6 at two points, what are the coordinates? I used Reiny's way to help solve this answer. Please check if I've done it correct: y'= 3x^2-16x+6 3x^2-16x+6=6 3x^2-16x=0 x(3x-16)=0 Solve for x's x=0 3x-16=0 ~> x=16/3 Plug x values to ...

### Math: Reiny

I already posted this question, and Reiny had a question about the question. How many square units are in the region satisfying the inequalities y>=(x) and y<=-(x)+3? Express your answer as a decimal. * the () are absolute value signs. •Math - Reiny, Wednesday, ...

### steve reiny reiny damon probability

buses arrive at the bus stop at 15min interval starting from 7am in the morning. If a passenger arrived at the bus-stop at a time that is uniformly distributed between 7 and 7:30am. what is the probability that the passenger waits less than 5minutes for a bus

### trig

e.g. tan 315 = -1, does that work in our equation ?? Yes, thank you again Reiny! My next question is to find sin theta and cos theta. cos 2theta = 1/3 and pi less than or equal to 2theta less than or equal to 2pi I hope Im not overburdening you with question:/

### reiny steve reiny damon!!! Damon help maths

If P(x) and Q(x) have a common factor (x- h),prove that (x-h) is also a factor of P(x)- Q (x).find the possible common factors when P (x)=ax^3 + x^2 - 15x - 18 and Q(x)= ax^3 - 14x - 12.also find the corresponding value of a. Plz show me step of work

### Thank you Jiskha and Reiny

I just wanted to write a post to thank everyone who helps out. I haven't found people to be very grateful on this site so I thought i'd take a moment to tell you how awesome you guys are. Special thanks to Reiny for all the helpful math tips. You have helped me through a lot ...

### Reiny or Damon or Bobpursley

Express the series 11 + 18 + 27 +...+ 171 using sigma notation. Usually you would take 27-18 and that's the step between numbers, right? (I think its the k-value?) But 27-18=9 and 18-11=7. Are we stepping by k+2 here? Like k, k+2 k+4, k+6...? Please help me. I'm not confident ...

### trigonometry

---I asked this question Solve the following right triangles: a. a=117 ft, b=16.35 ft b. B=8 degrees 29',and a=32.8 ft Reiny was kind enough to post this reply. "solving" a triangle involves finding all missing sides and angles, so in a) you found the sides, but still no angle...

### Math( Attn: Reiny)

1. A rental business charges \$12 per canoe and averages 36 rentals a day. For every 50-cent increase in rental price, it will lose two rentals a day. What price would yield the maximun revenue? I was told the answer by Reiny, but I couldn't get the right answer. I found the ...

### DEAR REINY

dear reiny i am sim who posted 4 questions this morning i am in dubai and my final examinations are after 13 days and by the way those questions were not my homework or assignment those were some sums which we get on our school website and i had a doubt in those questions but ...

Opinions are ok but anything with identifying information will be removed. In fact, why don't you retype your question and omit the part about including name, address, et al. and we can get someone to remove your original post. ok.thanks,do you think you can reply also.?I'd ...

### Algebra

I already posted this question and Reiny answered it, I just wanted to clarify my answer Problem: If f(x) is a polynomial of degree 4, and g(x) is a polynomial of degree 2, then what is the degree of polynomial f(x)-g(x)? Reiny: so f(x) has to contain an x^4 term and g(x) does...

### Reiny! Reiny! Reiny! Answer Check and HW Help!

Translate to a system of equations and solve: 1) The sum of two numbers is 36. One number is 2 more than the other. Find the numbers. Answer: (17,19) 2) Find two numbers whose sum is 66 and whose difference is 18. Answer: (37,29) These ones I am not sure of: 3) The difference ...

### precalc

Suppose that z1=6-8i. Find: A. The Trig Form of the complex number z1, where your theta is in degrees. B. The Trig form of z1*z2, where z2=5[cos(60degrees)+isin(60degrees)] C. The Trig Form of (z1)^4

### calculus

1. what trig function has an amplitue of 1 and negative values for angles between π/2 and π? 2. what trig function never crosses the x-axis and has a value of 2 at π/6? are these correct? 3. what trig function has a period of π and is undefined for -π/...

### english

help me to reply this letter from a friend in Britain,this letter is in my english book is not real but i have to write a reply. I'd love to come and stay with you.It will have to be in August because ,as you know, our summer holiday are not as long as yours. Tell me when the ...

### math

Posted by connie on Monday, July 20, 2009 at 11:56pm. Find the indicated outputs for f(x) = 2x²-4x f(0)= ____? f(-1) =____? f(2) =____? Responses math - Reiny, Tuesday, July 21, 2009 at 8:00am f(0) = 2(0)^2 - 4(0) = 0*0 = 0 f(-1) = 2(-1)^2 - 4(-1) = 2(1) + 4 = 2 + 4 = 6 now ...

### math

could someone please refresh my memory of the basic trig functions? ex) cos^2 + sin^2 = 1? That is a trig identity. http://www.sosmath.com/trig/Trig5/trig5/trig5.html

### steve reiny proportion help maths reiny!!!

The illumination of a small object by a lamp varies directly as the candle-power of the lamp and inversely as the square of the distance between the lamp and the object.If a light-bulb of 8 candle power,fixed 150cm above a table,is replaced by a 5 candle power bulb,how far ...

### trig

What kind of reflections are the following trig functions? y = 3cos(x-1) y = sin(-3x+3) y = -2sin(x)-4

### trig

What is the shift along x of the following trig functions? y = (3sinx/2) + 4 y = -2sin(x)-4 y = sin(-3x + 3)

### trig

express the trig. ratios sinA,secA n tanA in terms of cotA.

### Trig

Find (if possible) the trig function of the quadrant angle. sec 3pi/2

### trig

What kind of reflection does the trig function y = cos(4x/3 minus 1) have?

### trig

What kind of reflection does the trig function y = cos(4x/3 minus 1) have?

### trig

how do i do this? give the signs of the six trig functions for each angle: 74 degrees?

### trig

simplify to a constant or basic trig function.. 1+tan(x)/1+cot(x)

### trig

find the 5 trig ratios when sin theta = -5/13 and lies in quadrant 3

### Trig

Does anybody know a good website that will help me with finding the six trig functions of a point NOT on the unit cricle?

### trig

use the unit circle to find the exact value for all the trig functions of è=2ð/3.

### Precalculus

How would you solve this trig function: cos2x=sin^2-2 how do you know what trig identities to use?

### Trig

find the exact values of the six trig functions of angle... sin(-315degrees) how do i do this?

### trig

I don't know to find the derivative of the following trig functions. Please help. f(x)= cotx h(x0= secx i(x)= cscx

### trig

I don't know to find the derivative of the following trig functions. Please help. f(x)= cotx h(x)= secx i(x)= cscx

### Math

To Reiny: Hi, thank you for your time Reiny and your info. I am so sorry but on the first one I accidentally put 0 where I should have put =9. In other words, the first equation should have said (9n+1)squared =9. Really sorry to have taken up your time with the wrong equation...

### trig

find the 5 other trig functions if cos(theta) = square root of 2/2 and cotangent is less than 0

### trig

if (-12,5) is a pointon the terminal side of an angel 0 find the exact value of six trig funcation of 0

### trig

what is the exact value of 7pi for all trig func.?

### Trig

Find (if possible) the trig function of the quadrant angle.

### trig

write a product of two trig functions that equals 1.

### Trig

Solve the following trig equation 2cos(x-π/6)=1

### Trig

csc thea= -2, quadrant 4. what are the six trig functions?

### trig

TRIG Identities, Gr. 12: Prove: cot4x=1-tan^2x/2tan2x

### Math

Mrs. Hart, at age 65, can expect to live for 25 years. If she can invest at 5% per annum compounded monthly, how much does she need now to guarantee herself \$900 every month for the next 25 years? math - Reiny, Friday, April 3, 2015 at 3:05pm Present Value = 900(1 - 1.0041666...

### trig

What is the shift along x of the trig function y = cos(4x/3 minus 1)? Any link of proof would be appreciated if you have one Thank you

### trig

What is the shift along y of the trig function y = cos(4x/3 minus 1)? Any link of proof would be appreciated if you have one Thank you

### trig

Let Q be an acute angle such that sinQ=.6. Find the values of the following using Trig Identities: cosQ and tanQ

### Trig

Use Trig identities to verify that sec^4(x)-tan^4(x)=1+2tan^2(x), Only work with one side of the equation

One more problem.. Given sin t= 3/11 and cos t<0, find the values of the remaining 6 trig functions.

### trig

how to i find the six trig values for (7pi/3)

### trig

what's the single trig. function of cos6xcosx-sin6xsinx

Reiny, thanks!

Thank you!

Thanks Mr Reiny

### Algebra 1 (Reiny)

1. t^-6 for t = 2 A: 1/64?

### Algebra 1 (Reiny)

1. ((d + 2)/(d + 8)) = ((-6)/(d + 8)) A: ? 2. 4/n^2 = 7/n + 2 A: n = -4 or n = 1/2? 3. 2/t + 4/3t = 4/t + 2 A: t = 10? 4. ((x -6)/(x^2-6)) = ((-4)/(x-4)) A: ?

### Science

Lack of oxygen in a pond may be a limiting factor. True or False? Please reply ASAP, thanks Lack of oxygen in a pond may be a limiting factor. True or False? Please reply ASAP, thanks Please only post your questions once. Repeating posts will not get a quicker response. In ...