Warning: Illegal string offset 'html' in /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php on line 909

Warning: Cannot modify header information - headers already sent by (output started at /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php:909) in /home/hsn/public_html/forum/admin/sources/classes/output/formats/html/htmlOutput.php on line 114

Warning: Cannot modify header information - headers already sent by (output started at /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php:909) in /home/hsn/public_html/forum/admin/sources/classes/output/formats/html/htmlOutput.php on line 127

Warning: Cannot modify header information - headers already sent by (output started at /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php:909) in /home/hsn/public_html/forum/admin/sources/classes/output/formats/html/htmlOutput.php on line 136

Warning: Cannot modify header information - headers already sent by (output started at /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php:909) in /home/hsn/public_html/forum/admin/sources/classes/output/formats/html/htmlOutput.php on line 137

Warning: Cannot modify header information - headers already sent by (output started at /home/hsn/public_html/forum/cache/skin_cache/cacheid_1/skin_topic.php:909) in /home/hsn/public_html/forum/admin/sources/classes/output/formats/html/htmlOutput.php on line 141
Yet another Differentiation question - HSN forum

Jump to content


Yet another Differentiation question


2 replies to this topic

#1 Pammy

    Site Swot

  • Members
  • PipPipPipPip
  • 194 posts
  • Location:Glasgow(ish)
  • Interests:Swimming, music (listening and playin), goin to the flicks, shopping <3, shoes, glitter, reading, flowers, msn, bowling for soup, westlife, bags and nailpolish
  • Gender:Female

Posted 02 February 2007 - 08:36 PM

Hello all
I'm stuck again, and any help would be appreciated

Differentiate: -2 cosec power4.gif x

So I did this : = (-2 cosec x) power4.gif
dy/dx = 4. -(-2 cosec x cot x)(-2 cosec x) power3.gif
= 8 cosec x cot x . -2cosec power3.gifx
= -16 cosec power4.gif x cot x


But the answer is....... 8 cosec power4.gifx cot x

Can anyone shed a little light on this for me ??
Thanks in advance !!
*~* Pam xxx *~*
*~* Kiss me, beneath the milky twilight, lead me, out on the moonlit floor, lift your open hand, strike up the band and make the fireflies dance, silver moon sparkling, so kiss me *~*

#2 ad absurdum

    Top of the Class

  • Members
  • PipPipPipPipPip
  • 390 posts
  • Location:Cambridge
  • Interests:Muzak.
  • Gender:Male

Posted 03 February 2007 - 11:22 AM

You're very close, but I think the problem is how you are taking this "-2". I don't think this should actually be taken in the brackets at all, the only part that is raised to the 4th power is the cosec x part. If you leave the -2 outside all your differentation and just differentiate (cosec x)^4, then multiply by -2 at the end, then you should get the answer.

Also, the way you've multiplied out (-2 cosec x)^3 isn't quite right, you need to take everything in the bracket to the third power, so you should end up with -8cosec3x.
HMFC - Founded 1874, beefing the Cabbage since 1875

#3 Pammy

    Site Swot

  • Members
  • PipPipPipPip
  • 194 posts
  • Location:Glasgow(ish)
  • Interests:Swimming, music (listening and playin), goin to the flicks, shopping <3, shoes, glitter, reading, flowers, msn, bowling for soup, westlife, bags and nailpolish
  • Gender:Female

Posted 04 February 2007 - 01:04 PM

Thanx very much !!
I understand where I went wrong now !!!
*~* Pam xxx *~*
*~* Kiss me, beneath the milky twilight, lead me, out on the moonlit floor, lift your open hand, strike up the band and make the fireflies dance, silver moon sparkling, so kiss me *~*





1 user(s) are reading this topic

0 members, 1 guests, 0 anonymous users