4 cos (2x - (pi /4) )

Rammstein666

Hi guys, umm...could some1 please give me a hand on this question-i just dont know where to start o :frown:

Q) If y = x^2 - x show that the derivative= 1 + ( 2y/x)

Thanx!!

Reply 1

m:)ckel

dy/dx = 2x-1

1+(2y/x) = 1 + 2(x^2 - x)/x = 1 + (2x^2 - 2x)/x = 1 + 2x - 2 = 2x-1

So we've shown dy/dx = 1 + (2y/x)

..I don't get the thread title btw.

Reply 2

Retropmot

y = x^2 - x
dy/dx = 2x - 1

but as y=x^2 - x = x(x-1)
y/x = x-1
2y/x = 2x - 2

so you can write 2x - 1 as 2y/x + 1

so dy/dx = 2y/x + 1

Reply 3

Rammstein_666

thanks! lol, i understand it now. =)

Umm, the thread title...lets not go there lmao-i put it in there by accident, almost posted in the wrong qs & forgot 2 change the title anna. soz, lol

Reply 4

Rammstein_666

hey-i thought i changed ma name o.0 2 rammstein666, grrrrrr

Reply 5

m:)ckel

Wtf is going on? Who's rammstein666?? And who are you??!

Reply 6

Rammstein666

Soz i dun know what happened there-i changed ma user name from Chrissi131 to Rammstein666. Bk 2 normal anywho

Reply 7

m:)ckel

But..but..if you changed your username, then all your posts (past and present) should be under the same name (so those chrissi ones should change too).

Or do you have 2 accounts? (and logging into each back and forth)