# Search results

1. ### I got one problem

Homework Statement integral of csc^3(x)cot(x) Homework Equations I tried using trig identity 1+cot^2(x)=csc^2(x) but I got result where I cancelled my indegrals. The Attempt at a Solution I tried to substitute the above mentioned indentity for csc^2 but I end up getting -cscx +...
2. ### I got two problems

Homework Statement I need to find the integral of (e^3x)cos(2x) Homework Equations The Attempt at a Solution I tried using different trig identities for cos(2x) to get a better equation and then tried to do few versions using the integration by parts but they all kept getting...
3. ### Find the derivative of the inverse function

So I need to find the derivative of the inverse function. I know that f is one-to-one and is continous. Also I know that f'(x)=1+[f(x)]^2. I found the inverse writing my equation like f(x)=x+(1/3)[f(x)]^3 then I switch the variables and get that my inverse function=(1/3)x^3 - x. Then I just take...
4. ### Find ln using differentials.

So the problem says "Taking ln10=2.30 estimate ln10.3 using differentials." The only thing I thought of doing was to set an integral from 1 to 10.3 with 1/x being the equation I integrate, but I'm not sure if that is right. Any help?
5. ### Purdue vs. Illinois

Hi, I got accepted to Purdue and University of Illinois at Urbana-Champaign, both in Electrical Engineering. Now it it would be time to decide which one to pick, and I have some trouble doing that. I mean I'm mostly interested in studying Power Engineering and maybe minor in physics. So I would...
6. ### I need some help.

The problem says that if y=e^nx, then d^ny/dx^n=? I got that the result is n^2e^nx, but it is not among the offered choices. Can someone tell what did I mess up? Thanks.
7. ### I'm stuck

Alright, here is the problem. For all real numbers x, f is differentiable function such that f(x)=f(-x). Let f(p)=1 and f'(-p)=5, for some p>0 a) Find f'(-p) b) f'(0) c) If L1 and L2 are lines tangent to the graph of f at (-p,1) and (p,1) respectively, and if L1 and L2 intersect at...
8. ### Range problem

f(x)=5^sqrt(2(x^2)-1) I got that range is (1, to infinity) Is it correct?
9. ### Could you check this please

f(x)=e^cosx equation for the axis of symmetry??? I got x=pi f(x)=ln(x^2 - 20) describe symmetry?? I got symmetric arround y axis. inverse?? I got y=sqr of ((x/ln) +20) f(x)=ln(x^2) Inverse??? I got y= sqr of (x/ln)
10. ### Testing I got question about the new SAT

Does anyone know what are minimum scores for University of Illinois at Urbana Champaign, North Carolina State University, and Purdue?
11. ### I got a question.

Let's say that somehow a car moved with speed greater than the speed of light, would that mean that time is going backwards?
12. ### Question about integrals

Hmmmmmm...Well I guess my first question is how do I write the integral...Do I have to have some sort of program or...??? Anyway, lets say I have some kind of simple integral and there is dx in front of it. What is that dx there for.
13. ### Acceleration question

What acceleration does a rocket need to reach speed of 200 m/s at height of 1.0km. I know that acceleration is velocity over time but I have only velocity and distance. :confused:
14. ### Suppose that the function T has period 7 and that T(0)=3

Suppose that the function T has period 7 and that T(0)=3. Explain why T(-30)=T(40)? Is it normal that teacher just tells you to read stuff in book and then do your homework, without explaining it? She was "teaching" some stupid stuff about graphing f(x)=(x-1)^2 + 2, which they teach you...
15. ### I got question

In Friday we did simple lab in Physics. We took ball and dropped it measuring dropping height and rebound height. We did 10 trials and 10 times for every trial. We started from 100 cm and went all the way to 10 cm. Then we made a model y =0.75x+2 cm. Where x is dropping height in cm and y is...
16. ### Write f as piecewise defined function

Let f(x)=x+|x| and g be defined by the rule "g(x) is the slope of the graph pf f at x". Write f as piecewise defined function. :confused:
17. ### Programs After getting bachellors degree in Engineering

can you go for Phd in Physics? Do you have to go all over again or can you emmediatley go for masters and then phd? bechellor
18. ### Big trouble coming from Siberia

Warming hits 'tipping point' Siberia feels the heat It's a frozen peat bog the size of France and Germany combined, contains billions of tonnes of greenhouse gas and, for the first time since the ice age, it is melting Ian Sample, science correspondent Thursday August 11, 2005 The...
19. ### Why don't they use Pyromagnetic Generators in nuclear power plants?

I just read some stuff on pyromagnetic generators, and my first thought was why don't they use the pyromagnetic generators in nuclear power plants and in any power plants that use thermal energy? You would skip conversion from thermal to mechanic, and then from mechanic to electric. I'm sure...
20. ### What Engineering to study

When I look at all different kinds engineering I just get lost and don't know which one to pick. I wish I had time to study them all but unfortunately I don't. I was always obsessed with the airplanes and always wanted to be a pilot. Well I'm to tall to be a pilot so I gotta change to something...
21. ### Civil engineering

What civil engineering departments in the U.S. would you recomend? Also what would be a good major/minor to combine with civil engineering (Construction Engineering)?
22. ### Why light travels

How does light travel? What gives the energy to the photons to travel at c? And if in order for something to travel at c you need an infintie amount of energy, how come photon travels at c?
23. ### Can a Black Hole create Supernova?

Can a Black Hole create Supernova??? Is it possible that a Black Hole gets too big, and then just explodes under the pressure of it's own mass. Like a balloon that explodes because we blow it to much. Is it possible that a Black Hole can have a critical mass at which it simply explodes? :confused:
24. ### Schools Questions about Colleges

Besides the obvious one MIT, what other colleges would you recommend for the following majors Nuclear Engineering EE Aeronautical Engineering And I would also like to know how good Purdue is in those majors. Thanks in advance. :smile:
25. ### Why does light accelerates after being slowed down

I read about Cherenkov's effect and how light slows down if it goes through, lets say, water. My question is how it can speed up again after it exits the water? :confused:
26. ### I got some questions

Hi there, I apologize for asking this many questions but I need help in deciding how and what to do in next few years. Alright, I came to the US about 2 years ago, and my English is getting better with every day. I will be Senior in the high school next year. I'm pretty good in math (knock on...
27. ### Wireless transmission of electricity

Is there any research done in this field? If there is why it was not realized by now? It is known that Tesla did some research on this topic but never got the funding for his Wardenclyffe Tower. I think that he managed to send electricity at about 40 miles without using any wires.
28. ### I need some guidance for next school year

Hi, I'm new member, and this forum looks like it might be helpfull for the next school year in which I will take Calculus. I'm sorry for my English but I live in USA for only few years. For now I would like someone to instruct me how to prepare for Calculus. I have a lot of free time now and I...