If x and y are defined in terms of a third vatiable say t , then to find d2y/dx2 , we cannot find d2y/dt2 and d2x/dt2 and divide them to get d2y/dx2 , i am unable to fingure out the reason for this !!!!!!!
a strange solution ??????
I was solving a tangent problem and came accross a strange thing ,
its a simple quadratic equation ,y2 - 4y -8 = 0 ,
by quadratic formula , y = 2 + 2*31/2 and 2 - 2*31/2 ,
now if i write the same quadratic as (y-2)2 = 12 ,
then i apply square root function on...
I have a relation xy=c2 , if i apply implicit differentiation to both sides i get dy/dx =-y/x , but if i write the same thing as y=c2/x , then dy/dx comes out to be -c2/x2 , whats going wrong ??????
Does the second derivative test fail for x3 at x=0:
f'(x)=3x2 f''(x)=6x ,
for x=0,
f'(0)=0 & f''(0)=+ve ,
so it should be a point of local maxima , but it is not!!!!!!!!!!
lim as h->0 (|(h^2) + 4h |)/h comes out = 4 when i do it by splitting the definition of function according to modulus , but if according to distributive property of modulus , i can also write it as lim as h->0 (|h|/h)|((h) + 4|)) , but im as h->0 (|h|/h) does not exist , so whats wrong????????
This is in continuation to https://www.physicsforums.com/showthread.php?t=330495
The question that initiated my doubt reads this -- " the internal resistance of an accumulator battery of emf 6V is 10 Ohm when fully discharged . as battery gets charged up , its internal resistance drops to 1...
My doubt is that when we charge a battery we say that energy is transferred into it , but does the emf of a battery change in this process ? Is the emf same before and after charging , if yes then what actually happens during charging a battery ??
pls help !!!!!!!!!!!