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2. ### Volumes last week of calc

righttt pi [(1/-1)x^-1]

(-1/3)x^-3
4. ### Volumes last week of calc

since it's divided by 1, isn't it negative n =x^-2
5. ### Volumes last week of calc

\pi [ \frac{x^{-3}}{-3}]
6. ### Volumes last week of calc

\pi \int^{2}_{1} \frac{1}{x^2} dx
7. ### Volumes last week of calc

\int^{1}_{2} \pi [\frac{1}{x}]^2 dx if you help me with this problem, i am sure i will get the rest of the problems.
8. ### Volumes last week of calc

[SOLVED] volumes... last week of calc i was absent when we went over the volume section. y= 1/x, x= 1, x= 2, y= 0,; about the x-axis \int^{1}_{2} \pi \frac{1}{x} dx i don't know what's next. can anyone inform me, please
9. ### One last optimization problems

am soo stupid...thanks
10. ### One last optimization problems

2x^2 - x^2 - 1 = x^2 - 1 it might sound childish, but how is that equal? you can't factor anything or simplify it
11. ### One last optimization problems

\frac{2x^2- (x^2+ 1)}{x^2}= \frac{x^2-1}{x^2} how are they equall?
12. ### One last optimization problems

so, i was right?
13. ### One last optimization problems

how are they equall?
14. ### One last optimization problems

\frac{(2x)- (x^2+1)}{x^2}= \frac{x^2- 1}{x^2} how are those equal?

whaaat
16. ### One last optimization problems

thats what i got to so far (x^2 + 1)/ x 0=({{2x^2}-{x^2}+{1}})/{x^2} which is undifined... NO answer
17. ### One last optimization problems

do u want me to use the quo rule for 1/x which is -1/x^2?
18. ### One last optimization problems

1 + ln x =0 -1 = ln x thats about all i can do
19. ### One last optimization problems

[SOLVED] one last optimization problems Homework Statement find two positive numbers such that the sum of the number and its reciprocal is as small as possible. Homework Equations x+(1/x) = s f' =1 + ln x The Attempt at a Solution lost
20. ### Another cool optimization problem

thanks alot. care for one more problem?

y= 25
22. ### Another cool optimization problem

find the derivates of 50x-x^2 50-2x=0 x=25 100=2(25)+2y
23. ### Another cool optimization problem

y = (100/2)-x
24. ### Another cool optimization problem

am trying to solve for y
25. ### Another cool optimization problem

2y = 100/2x y = (100/2x) * .5
26. ### Another cool optimization problem

Homework Statement find the dimensions of a rectangle with perimeter 100m whose area is as large as possible Homework Equations area = XY 100 = 2x + 2y y= 100/4x x(100/4x) (400x - 400x)/16x^2 1/16x^2 = 0 The Attempt at a Solution well... am lost
27. ### Simple optimization problem

thanks alot. am messed up today!
28. ### Simple optimization problem

x=\sqrt{1000}=\sqrt{10\cdot10^2}=10\sqrt{10} how did u get that?
29. ### Simple optimization problem

x=square root of .001?

2/1000=x^-2
31. ### Simple optimization problem

2-(2000/x^2)=0 i think
32. ### Simple optimization problem

[SOLVED] simple optimization problem Homework Statement find the dimensions of a rectangle with area 1000 m^2 whose perimeter is as small as possible Homework Equations perimeter = 2x + 2y area = xy 1000 = xy y= 1000/x perimeter = 2x + 2(1000/x) The Attempt at a...
33. ### Rational expressions very simble, but hard for me

but the b's (x and y) doesn't cancel since they have two different signs

35. ### Easy chain rule for you guys

\frac{dy}{dx} {y= 2x^{sinx}} product rule f= 2 f'= 0 g= x g'=? chain rule f= x f'= 1 g=? g'=? is the anser y'=-2x^{cosx}
36. ### Easy chain rule for you guys

or maybe the answer is y=-2cosx
37. ### Easy chain rule for you guys

y=2x^{sinx} i know i should use the product rule within a chain rule. but how can i use chain rule with sinx is the anwser y=-2x^{cosx} can anyone give me pointer to this easy problem and tell if am forgetting something.
38. ### Another chain rule: easy one

Y'= e^{-x2}(1-2x^{2}) thanks for the help
39. ### Another chain rule: easy one

Solved it thanks
40. ### Another chain rule: easy one

[SOLVED] another chain rule: easy one y=xe^{-x^2} i have no i dea how to start. f'= x^{x^2} or -2x^blah blah blah just get me started and i'll promise you i will finish it myself
41. ### First derivative: chain rule: easy for you guys

g'= -m Solved. thanks for the help
42. ### First derivative: chain rule: easy for you guys

lets just go back to the original equation fsingle-quote(x)=e^{g(x)}gsingle-quote(x) what is g'(X) equall to
43. ### First derivative: chain rule: easy for you guys

never mind, sorry.
44. ### First derivative: chain rule: easy for you guys

ysingle-quote=a+x\cdot0=a times 0 would be zero,right?
45. ### First derivative: chain rule: easy for you guys

gosh! well i would use the product rule or maybe not. f= x g=ax f'= 1 g'=product rule high school calc.
46. ### First derivative: chain rule: easy for you guys

how did you get g'(x) i thought the (m) was constant thus making the the derivative equal to 0

yes!
48. ### First derivative: chain rule: easy for you guys

[SOLVED] first derivative: chain rule: easy for you guys Y=E^(-mx) f= E^x g= -mx f'= E^x g'= o E^(-mx) * 0(E^(-mx)) i think, not sure though Y'= 0 which is wrong someone help
49. ### Magnetism Question

how should i break it down?
50. ### Magnetism Question

Homework Statement A high voltage power line carries a current of 110 A at a location where the Earth's magnetic field has a magnitude of .59 G and points to the north, 72 degrees below the horizontal. find the direction and magnitude of the magnetic force exerted on a 250-m lengh of wire if...