# Where has the 'X' gone???Watch

#1
where has the x gone from xln7 to the next step im confused?
0
9 years ago
#2
Looks like a typo (the derivative cant just be a constant for an exponential graph).

Oh I thought it was saying the derivative was just ln7 ^^ nvm
0
9 years ago
#3
Differentiate both sides with respect to y, then rearrange.
0
#4
oh i think i get it .....have they turned x>>>>>>>>>>1 by diffrentiating it?
0
9 years ago
#5
The X disapeared as it should. X multiplied by a number differentiated gives you the number without the X, therfore ln7. It wouldn't be just a constant because you'd multiply be y to get dy/dx = yln7, I think?
0
9 years ago
#6
(Original post by mathslover786)
oh i think i get it .....have they turned x>>>>>>>>>>1 by diffrentiating it?
Theyve just differentiated both sides. On the left hand side they've used the product rule, on the right just imagine y = cx where c is a constant, the gradient (or derivative) of this is just c because its a straight line. The constant in this case is ln7.
0
#7
Xln7 same as ln7 X?.....so when you diffrentiate you are left with just the number? have i got that rite?
0
9 years ago
#8
(Original post by mathslover786)
Xln7 same as ln7 X?.....so when you diffrentiate you are left with just the number? have i got that rite?
xln7 =/= ln(7x) read my post above
0
9 years ago
#9
Hope this helps....
0
9 years ago
#10
(Original post by mathslover786)
where has the x gone from xln7 to the next step im confused?
it didn't love you back, so it ran off.
0
9 years ago
#11
(Original post by Tinkerbelle ♥)
it didn't love you back, so it ran off.
lol
0
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