simple

1. Simple derivative to find rate of change

I'm having a problem with a practice problem. So if you want to find the rate of change of x (on a right triangle) and only know that Y is a constant 20ft, the radians of the angle between x and the hyp is .15 radians and also that the radian measure is going up by .1 every minute (0.1rad/min)...
2. I know this is probably simple but...

So I have this practice sheet and they give you the answers in the back of the book but I am not getting the how part of this and I'm afraid I'll have a test and be stuck. If anybody can explain what I am supposed to do to get these answers that would be great (Thinking) oh and sorry about the...
3. Physical Pendulum

A pendulum consists of a tiny bob of mass M and a uniform cord of mass m and length L. (a) Determine a formula for the period. (b) What would be the fractional error if one used the formula for a simple pendulum?
4. Simple area question

Im stuck on this question What is the total area of the car park, office block A and office block B in square meters (m2)? A. 3999.21 m2 B. 298.88 m2 C. 2780.75 m2 D. 1616.91 m2 E. 580.62 m2 I can't seem to get an answer that matches from one of the above, i have tried to add all the areas up...
5. Integrating Velocity in the Simple Harmonic Oscillator

Obtain the displacement x as a function of time for the simple harmonic oscillator using the conservation of energy equation. [Hint: Integrate v = +-√[ k/m . (A^2 - x^2) ] with v = dx/dt.]
6. Help Needed Quickly on Original but Simple Research

Hello everybody! I recently conducted research where I ran protein powders through a spectrophotometer which gave out concentration values to compare to the label. I prepared 6 dilutions of the powder ranging from 100 to 600 micrograms/mL according to the nutrition label. I then ran 3...
7. Simple Harmonic Motion - General Solution

(a) Show that x = a sin ωt + b cos ωt is a general solution of the equation, d^2x/dt^2 + kx/m = 0, and (b) determine the constants a and b in terms of the A and Φ of the equation, x = A cos(ωt + Φ).
8. a simple combinatorics (i assume) problem

I feel that kind of problem should be very easy, but still got no clue how to solve it.(Thinking) Cars have 4 wheels, trikes - 3 wheels, trucks - 6 wheels. What's the number of all possible vehicle combinations that have a total amount of wheels of 50. Thanks.
9. Simple problems.

Hi, I am reviewing something, and now I feel pretty inadequate write 3 1/6 as a percent, round to nearest tenth of a percent. So It would be 316.7 percent?
10. Simple Harmonic Motion - Spring

A spring with spring constant 250 N/m vibrates with an amplitude of 12 cm when 0.38 kg hangs from it. (a) What is the equation describing this motion as a function of time? Assume the mass passes through the equilibrium point, toward positive x (upward), at t = 0.11 s. (b) At what times will the...
11. simple question on distributing a negative

with this rule in mind, can it be applied at will say to simplify an expression such as (1-x)/(x-1) to arrive at -1 i am confused because i was under the impression if you multiplied by a factor of 1 to the top of an expression then you also had to do so to the bottom.
12. Simple question for complex derivatives

For "If f(z) and g(z) are differentiable, so is f(z)+g(z)", they have to be differentiable at identical z right? Like say f(z)=z (differentiable for all z), and g(z)=|z|^2 (differentiable of all z except 0), the sum rule wouldn't work right?
13. Simple mathematical induction

Okay, so I've just started with mathematical induction today, and I've encountered a problem which I cannot seem to solve (probably because I haven't done any math related work in a long time). It's just the simple problem of proving the following: n^2>=2n+1 (for: n>=3) I've worked it out as...
14. Need elaboration on a simple probability question

Hi all, I'm doing some review and I am not totally comprehending a portion of one of the examples, hoping someone can elaborate on what is actually being said. [Question] If there are 11 strangers in a room, what is the probability that no two of them celebrate their birthdays in the same...
15. Simple Linear Regression Model

Let a simple linear regression model be: Y_i=\alpha +\beta x_i + e_i \ \ \ (i=1, \cdots ,n) e_i\sim N(0,\sigma ^{2}) Least squares estimator of \alpha , \beta are: \hat{\alpha }=\bar{Y}-\hat{\beta}\bar{x}, \hat{\beta}=\frac{S_{(xY)}}{S_{(xx)}} (S_{(XY)} is defined as...
16. Showing that there is no simple group of order 6p^r

Show that there is no simple group of order 6p^r for any prime p and positive integer m.
17. Help with simple differentiation question

Hi, I am in the middle of Differentiating parametric equations however I got stuck and I was hoping someone could give me an answer. I need to differentiate with respect to x this equation: It looks simple but I have no idea how to do it, I tried searching the internet but I don't even know...
18. SImple interest

Quick Print Press borrowed $20,000 from the Provincial Bank on May 25 at 7.5 percent and secured the loan by signing a promissory note subject to a variable rate of interest. Quick Print made partial payments of$5000 on July 10 and \$8000 on September 15. The rate of the interest was increased...
19. Trying to solve a polynomial - probably simple

Hi, I'm trying to help a high-school sophomore with a math problem, and unfortunately my algebra days are long behind me. Here's the equation: x^3-9x-440=0 I know x=8, but I don't know how to find it. I'd appreciate some guidance. Thanks.
20. I know these questions are simple but that's what confuses me

So for the parts under question 1 from this sheet: Are my solutions enough? I'm just not sure if it's rigorous enough, whenever I have to "prove" something that seems obvious to me to be true it throws me off. Thanks :)