RunRyder RC
 1 page 402 views POST REPLY
HomeOff Topics › Help with calc II
04-25-2009 11:30 PM  9 years agoPost 1


Phoenix, Arizona

My Posts: All  Forum  Topic

For those RC heli guys who are good at math and remember calc II, we are just starting basic differential equations (separation by variables) and am stuck on these 4 questions

Find the solution to the differential equation below, subject to the initial condition

dB/dt+2B=88; B(1)=140 (I am pulling my hair out on this one)
my current answer is B(t)=(((-192/exp(-.5))exp(-.5t))-88)/(-2)
ANSWER: d(B)=44+96exp(2-2t)

dz/dt=2t(exp(z)); z(0)=0 EDIT: Finally got this one
ANSWER: d(z)=-ln(1-t^2)

dx/dt=(xln(x))/t; x(1)=2 EDIT: Got this one
ANSWER: d(x)=exp(ln(2)t)

x(x+1)du/dx=u^2; u(1)=1 EDIT: Got this one as well
ANSWER: d(u)=-1/(ln(2x/(x+1))-1)

Thanks for.......well, nothing LOL.
Perseverance wins the battle.

04-25-2009 11:47 PM  9 years agoPost 2



My Posts: All  Forum  Topic

Thanks dude,

Now my brain hurts

Seriously, wish I could help but have not done any calc in 30+ years.

Good luck,

Don't blame me, I did'nt vote for him.

PM  EMAIL  Attn:RR  Quote
04-26-2009 02:42 AM  9 years agoPost 3
Peter Wales

rrElite Veteran

Orlando Fl

My Posts: All  Forum  Topic

I explained this to the cashier in Publix this morning but she still wanted $115 for my groceries rather than the $8 I proved they really cost.

Peter Wales

04-26-2009 02:55 AM  9 years agoPost 4
GimbalFan (RIP)


Big Coppitt Key, FL

My Posts: All  Forum  Topic

↑↑↑ Bwahahahahahaha! Math humor -- too rare.

I'll guess that regardless of cost, those groceries ALL fit into one bag.


 1 page 402 views POST REPLY
HomeOff Topics › Help with calc II
 Print TOPIC  Make Suggestion 

 1  Topic Subscribe

Wednesday, December 19 - 1:08 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

The RC discussion world needs to consolidate. RR is now one choice for that. Its software is cutting edge. It hosts on-topic advertising. Help RR increase traffic buy making suggestions, posting in RR's new areas (sites) and by spreading the word.

The RunRyder Difference

• Category system to allow Rep/Vendor postings.
• Classifieds with sold (hidden) category.
• Classifieds with separate view new.
• Answer PMs offsite via email reply.
• Member gallery photos with advanced scripting.
• Gallery photo viewer integrated into postings.
• Highly refined search with advanced back end.
• Hosts its own high end fast response servers.
• Hosts thousands of HD event coverage videos.
• Rewrote entire code base with latest technology.
• No off-topic (annoying) click bait advertising.
Login Here
 New Subscriptions 
 Buddies Online