squared

  1. J

    Derivative of a Squared Root

    y = [(x^2 + 1)^2]^(1/2) dy/dx = ?
  2. J

    Domain of a Function

    How to find the domain of the function. 3/(1 +(4/x^2))^(1/2) when I set the denominator equal to zero, I get stuck 1 + (4/x^2) = 0 x^2 + 4 = 0 x^2 = -4 now cannot take the root of negative
  3. M

    summation of alternating squared numbers

    Hello I have been stuck on this exercise for quite a while now: Show that: \sum_{k=1}^{n}(-1)^k\cdot k^2=\frac{n\cdot(n+1)}{2} by using these two summation formulas: \sum_{k=1}^{n}(2k)^2=\frac{2n\cdot(2n+1)\cdot(n+1)}{3} and \sum_{k=1}^{n}(2k-1)^2=\frac{4n^3-n}{3} My initial guess was...
  4. B

    Least squared line of best fit - negative coefficient for y intercept

    Hi I have a set of data that compares arm bone length (the predictor) with height (the response). I am having to read ahead due to deadlines so am hoping I have got this right. As I understand it the basic form of the least squared line of best fit is determined by (in its most general form)...
  5. S

    x squared

    Hello I have something like this : u_{n+1}-u_n = 3(u_n^2 -u_n) +1 = 3(u_n - \frac{1}{2})^2 + \frac{1}{4} Can someone explain to me how they went from u_{n+1}-u_n = 3(u_n^2 -u_n) +1 TO 3(u_n - \frac{1}{2})^2 + \frac{1}{4} Thank you very much
  6. O

    Casio fx-100AU PLUS - problem using squared function with negative numbers

    Hello I am new to doing maths and bought a CASIO fx-100AU PLUS. Is this a good choice? I am allowed any scientific or graphics calculator for doing calculus. Also I am confused, when I type in -1 squared it says -1 but -1 times -1 = 1? What am I doing wrong? Thank you
  7. L

    Y prime squared?

    I am not sure how to go about this question. y^2+(y')^2=1 Any help is highly appreciated!
  8. H

    Mean squared error.

    Could you please explain mean squared error and its practical application?
  9. A

    Chi Squared Distribution

    Hello everyone, I'm having some trouble with this question : Suppose that X1 and X2 are independent N(0, 4) random variables. Compute P(X12 < 36.84−X22) I don't really know how it works for a difference of a chi squared distribution. Thank you in advance !
  10. M

    Relationship between Sum of squared error and variance

    Hello, Please what is the relationship between Sum of squared error and variance? Is it possible to scale up the Sum of squared error to a factor, say 10, and does it automatically imply the variance too has to be scaled up with the same value, 10? If this is possible, what mathematical...
  11. A

    Absolute Value of X squared

    Hello, is there anybody who can help me with Absolute Value? I've just started taking 1st yr Calculus and got stuck on the review material.. It says to rewrite | x2+1 | without using the absolute value and the solution sheet says x2+1 is the answer. I thought there's gonna be two answers...
  12. A

    Is the square root of z multiplied by the square root of z* equal to mod(z) squared?

    I am a bit confused about the rule about "passing" the root: \sqrt { z } \sqrt { z } = \sqrt { z*z } \sqrt { z } \sqrt { z } = \sqrt { z*z } Is this true?
  13. W

    Squared Trigonometric Identity

    So I determine it as: It returns a decimal, whereas the answer is 50+ deg... What am I doing wrong?
  14. maxpancho

    Domain of a function squared

    Don't really understand the steps, and the answer was actually quite confusing to me. Might as well give me a hint :). Thanks.
  15. J

    Leg squared theorem

    I took notes in class on this theorem, but still don't understand how to do it. Can someone explain how this works/what to do?
  16. A

    infinity squared /(e^infinity squared)

    \frac { { \infty }^{ 2 } }{ { e }^{ { \infty }^{ 2 } } } does this go to one or zero? it is either 1 because the two infinities cancel out or 0 because the denominator must be greater than the numerator so the bottom infinity overtakes the top infinity which one is it? can anyone provide...
  17. L

    F-test or Chi Squared

    I unfortunately missed a fairly large chunk of the time that the Chi-squared stuff was covered in class, so I find myself suddenly wondering when it should be applied, versus an F-test. Without going to technical, can someone give me a fairly rough idea? From what it seems to me, you would use...
  18. K

    the expectation of the sum of yi minus ybar squared

    In general what is the expectation of the sum of yi minus ybar squared E(\sum( y_i - \bar{y})^2) = E(\sum( y_i^2 - 2\bar{y}y_i + \bar{y}^2)) = E(\sum y_i^2 -\sum \bar{y}^2)) = \sum E(y_i^2) -\sum E(\bar{y}^2) is this the same as the sum of of VAR(Y)?
  19. K

    primes squared inf showing a pattern with the last digits

    1. so if i take a prime and square, cube, etc inf times, the last numbers will (so far) be four numbers repeating inf. 2. if i take 5 to the 3rd power and up inf times the last 3 numbers will alternate between 125 and 625. My background in this is type of working numbers is non existent. Up...
  20. L

    How can a be irrational if it's exponent is an integer?

    I have the following problem: Prove that if ab is irrational for any arbitrary positive integer b, then a is irrational. I was thinking that if a was already an irrational number like the square root of 2. and b was equal to 3 then I would have the cubed root of 22 which is : 1.58740105197...