Sunday
December 4, 2016

Number of results: 4,546

For Reiny
If you could go back and check my reply to you. thanks
September 5, 2012 by Vanilla Bear

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 ...
January 3, 2011 by Carol

Reiny+Damon
Can you reply to my last math+log post =) thanks. I'm going to be having alot of math questions today.
February 23, 2009 by Chopsticks

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 ...
June 5, 2016 by Anonymous

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
February 21, 2012 by Anonymous

To Reiny
Reiny could you please check my Calculus post below, it says Calculus--Reiny.
October 4, 2011 by -Untamed-

trig
Solve without using a calculator or tables cos(5pi/6 + pi/4) Thank you Reiny!:)
May 1, 2008 by Priya

trig
Solve the given triginometric equation analytically 7 sinx - 2 = 3(2 - sin x) If your are online, thank you my dear Reiny:) Priya
May 1, 2008 by Priya

Math (Reiny??)
Mrs. Reiny ... As in Harris County Mrs. Reiny?
April 26, 2011 by sa

Reiny+ In need of help
Hey Reiny, could you please take a look at my expo growth and decay post? Thanks alot.
March 2, 2009 by Chopsticks

Reiny
Reiny I think I have found out the rectangle problem. Could you check and see if Ive got it correct?
January 19, 2011 by Sydney

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 ...
April 30, 2007 by jacob

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.
February 5, 2009 by Ellen

can someone reply to my last chem post
February 4, 2009 by Chopsticks

reiny
reiny why are you so smart thanks for aswering my question
July 25, 2012 by amira

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.
May 1, 2008 by Priya

Can someone reply to my previous post.
January 15, 2009 by Chopsticks

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.
March 1, 2007 by jas20

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 ...
April 18, 2007 by abdo

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 ...
January 24, 2010 by April

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
December 5, 2013 by BARBIE LEE

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?
November 12, 2009 by jane

Jiskha
Jiskha homework help rocks. But I need someone to reply to my post: social studies!!!! -afton PLEASE REPLY!!!!!!!!!!! 10/9 - 9:21 pm
October 9, 2006 by Anonymous

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 ...
December 25, 2011 by -Untamed-

January 21, 2009 by Chopsticks

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 = ...
December 13, 2010 by Anna

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'...
September 4, 2013 by Gabby

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...
February 23, 2009 by hayden

to reiny
Reiny i got (x+5)(x-3) x=-5 or x=3
December 28, 2008 by kiearra

Math thanks, Reiny
Thanks Reiny!
September 19, 2009 by Michael

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?
June 24, 2008 by Bell

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 ...
October 17, 2012 by Shreya

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...
May 7, 2013 by Gabby

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 ...
January 25, 2015 by maribel

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 ...
October 10, 2016 by Angie

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 ...
October 10, 2016 by Angie

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, ...
December 3, 2014 by Jenny

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:/
May 1, 2008 by Priya

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 ...
January 17, 2013 by Anonymous

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 ...
April 27, 2012 by Tabby

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 ...
January 25, 2015 by Wendy

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...

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 ...
February 13, 2016 by sim

Thank you (bobpursley)! (no reply needed)
January 13, 2007 by EinstNewtLieb

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...
November 12, 2014 by Trish Goal

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 ...
February 9, 2007 by DrBob222

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 ...
February 12, 2009 by Britney

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
December 5, 2011 by Joshua

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 ...
July 21, 2009 by connie

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/...
September 28, 2015 by anon

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...
September 28, 2010 by Anonymous

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
April 12, 2007 by raychael

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...
November 3, 2013 by Brandi

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...
April 3, 2015 by Judy

trig
What kind of reflections are the following trig functions? y = 3cos(x-1) y = sin(-3x+3) y = -2sin(x)-4
April 21, 2008 by Joshua

trig
What is the shift along x of the following trig functions? y = (3sinx/2) + 4 y = -2sin(x)-4 y = sin(-3x + 3)
April 21, 2008 by Amandeep

trig
express the trig. ratios sinA,secA n tanA in terms of cotA.
May 7, 2011 by Anonymous

trig
May 9, 2011 by Tor

Trig
Find (if possible) the trig function of the quadrant angle. sec 3pi/2
June 6, 2011 by Master chief

trig
What kind of reflection does the trig function y = cos(4x/3 minus 1) have?
April 21, 2008 by Priya

trig
What kind of reflection does the trig function y = cos(4x/3 minus 1) have?
April 22, 2008 by Chaitanya

trig
how do i do this? give the signs of the six trig functions for each angle: 74 degrees?
December 3, 2008 by Tay

trig
simplify to a constant or basic trig function.. 1+tan(x)/1+cot(x)
March 14, 2010 by hilde

trig
find the 5 trig ratios when sin theta = -5/13 and lies in quadrant 3
September 14, 2011 by karen

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?
September 16, 2009 by Anonymous

trig
use the unit circle to find the exact value for all the trig functions of è=2ð/3.
February 1, 2010 by Anonymous

Precalculus
How would you solve this trig function: cos2x=sin^2-2 how do you know what trig identities to use?
August 6, 2011 by Jess

Trig
find the exact values of the six trig functions of angle... sin(-315degrees) how do i do this?
September 1, 2011 by ALISON

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
January 19, 2012 by Claire

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
January 19, 2012 by Claire

trig
find the 5 other trig functions if cos(theta) = square root of 2/2 and cotangent is less than 0
June 9, 2010 by kelly

trig
if (-12,5) is a pointon the terminal side of an angel 0 find the exact value of six trig funcation of 0
June 19, 2014 by sal

trig
what is the exact value of 7pi for all trig func.?
February 1, 2010 by claire

Trig
Find (if possible) the trig function of the quadrant angle.
June 6, 2011 by Master chief

trig
write a product of two trig functions that equals 1.
November 6, 2011 by Dani

Trig
Solve the following trig equation 2cos(x-π/6)=1
January 31, 2012 by Matt

Trig
csc thea= -2, quadrant 4. what are the six trig functions?
May 6, 2013 by Shay

trig
TRIG Identities, Gr. 12: Prove: cot4x=1-tan^2x/2tan2x
May 23, 2013 by Josh

probability
Reiny, thanks!
September 24, 2011 by dee

ThankYou Reiny!!!
Thank you!
January 29, 2012 by Betty

Maths
Thanks Mr Reiny
May 12, 2013 by Gibbs

Algebra 1 (Reiny)
1. t^-6 for t = 2 A: 1/64?
January 31, 2014 by Anonymous

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: ?
June 3, 2014 by Victoria

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
April 21, 2008 by Priya

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
April 21, 2008 by Priya

trig
Let Q be an acute angle such that sinQ=.6. Find the values of the following using Trig Identities: cosQ and tanQ
July 27, 2010 by student

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
March 1, 2011 by Anonymus

One more problem.. Given sin t= 3/11 and cos t<0, find the values of the remaining 6 trig functions.
January 27, 2016 by Jane

trig
how to i find the six trig values for (7pi/3)
January 12, 2010 by Rak

trig
what's the single trig. function of cos6xcosx-sin6xsinx
May 17, 2012 by MIK

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 ...
May 18, 2007 by Marry

trig
Suppose that q is in standard position and the given point is on the terminal side of q. Give the exact value of the indicated trig function for q.
February 21, 2011 by Anonymous

THANKS FOR YOUR HELP DAMON AND REINY!! :)
thanks alot!
May 8, 2008 by Miley

algebra
Thank you Poppy and Reiny!!!!!!!!!!!! :)
May 5, 2010 by paul

Algebra 1 (Reiny)
12a - 11 = 9a - 1?
October 7, 2013 by Anonymous

Algebra 1 (Reiny)
Is -1/64 the answer to 2x^0y^-3?
January 18, 2014 by Anonymous

Math @Reiny
Did I do #2 right? 2.) (1-2i)/2i (1-2i)/2i = (1-2)/i x i/i = (1i-2i)/i^2 = (1i+2) =2+1i
October 8, 2014 by Ben

math
A lady buys goods worth Rs.200 from a shop. (shopkeeper selling the goods with zero profit) .. The lady gives him 1000 rs note. The shopkeeper gets the change from the next shop and keeps 200 for himself and returns Rs.800 to the lady. .. Later the shopkeeper of the next shop ...
March 10, 2014 by faizanurrahman

trig 26
simplify to a constant or trig func. 1. sec ²u-tan ²u/cos ²v+sin ²v change expression to only sines and cosines. then to a basic trig function. 2. sin(theta) - tan(theta)*cos(theta)+ cos(pi/2 - theta) 3. (sec y - tan y)(sec y + tan y)/ sec y combine fractions and simplify ...
March 14, 2010 by hilde

Reiny
Can u answer my last alg post?
February 2, 2009 by Chopsticks

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