need help and show ur solution so i can understand it use implicit differentiation
\[x(x+y)=x ^{4}y ^{2}-y\]
ok, try to do what comes naturally .. what do you come up with?
you know product rule and power rule .... those dont change
plss show how u solve it . im confused in this problem
i need to see your confusion to know where it resides. show me what you think should happen .... lets start with one piece of it, you see its a product .... what should we apply? x(x+y)
\[x ^{2}+xy\]???
i really dont know
wasnt what i was going for, but that is a correct move nonetheless so, what is the d/dx of x^2?
what do you normally do when you see x^2 ?
2x
good now, is that other term, xy, a product?
no????
xy means x times y and a product is math vocabulary for: "we multiply things together"
xy is a product of x times y, therefore it IS a product what is the product rule for derivatives?
xy
spose we have to functions f(x) and g(x); or simply f and g the derivative of fg would simply be f'g + fg' does this ring a bell?
xy + xy' ???????
very close :) you prolly missed the x' mark by accident, but to conform this to what i said spose we have to functions x(x) and y(x); or simply x and y the derivative of xy would simply be x'y + xy' x' = dx/dx which is just 1 so we tend to exclude it x'y + xy' = y + xy'
ahhh
how did u get y+xy'??
i wrote it all out ... im not sure how much clearer i could have been with it. so far we got \[x(x+y)=x ^{4}y ^{2}-y\] \[x^2+xy=x ^{4}y ^{2}-y\] \[\frac d{dx}(x^2+xy=x ^{4}y ^{2}-y)\] \[\frac d{dx}(x^2)+\frac d{dx}(xy)=\frac d{dx}(x ^{4}y ^{2})-\frac d{dx}(y)\] \[\frac {dx}{dx}2x+\frac {dx}{dx}y+x\frac {dy}{dx}=\frac d{dx}(x ^{4}y ^{2})-\frac d{dx}(y)\] \[2x+y+xy'=\frac d{dx}(x ^{4}y ^{2})-\frac d{dx}(y)\] halfway there
the d/dx (y) at the end of it should seem easy enough all thats left is the product of the powers
you might notice that we havent learned any new derivative rules ....
im trying to understand it
lets try some side stuff; if i ask you what the derivative of x^3 is, what would you say it is?
3x^2
but your almost right, i never said to derive it "with respect to x" the derivative of x^3 is 3x^2 x' becasue of the chain rule
what is the derivative of 2y^2?
4y
dont forget the chain rule, without knwoing what the derivative is "with respect to" you have to pop out the prime of the variable derivatove of 2y^2 = 4y y'
what is the derivative of 6t ?
6
if the derivative is y?? you have to put the y'?
your confusing a derivative with " a derivative with respect to __" without knowing the "with respect to" variable we simply dont know that value of what the chain rule pops out
the derivative of y is: y' the derivative of r is: r' the derivative of p is: p' the derivative of B is: B' the derivative of 4g^3 is: 12g^2 g' the derivative of x^2y is: 2xx' y + x^2 y'
you only begin to learn derivatives "with respect to x" but thats just to baby you into derivatives
any of this making sense yet?
if not, then youve simply learned derivatives the wrong way
not yet
Join our real-time social learning platform and learn together with your friends!