<p>Hi, I have a couple of questions and hope that somebody can help me!</p>
<p>a) Is it correct that if I have two events A and B that if I want to find out the probability of event B OR event A happening OR both happening then:</p>
<p>Event A OR Event B OR Both: P(A) + P(B) - P(A) x P(B)</p>
<p>And therefore is it also correct if I want to find out the probability of ONLY A OR B happening
that this formula changes to:</p>
<p>Event A OR Event B: P(A) + P(B) - 2 P(A) x P(B)?</p>
<p>b) What exactly is the modulus of a complex number?</p>
<p>Barron’s says it is the square of the distance to the origin and therefore the product with the conjugate of a certain complex number. But in the corresponding exercises it seemed that the distance itself it the modulus - maybe a mistake of Barron’s…</p>
<p>c) Can somebody explain to me how I can determine the Standard Deviation of a certain set of numbers with my TI NSpire CAS? What command do I have to look for? And how do I enter it?
Under LIST MATH I have two different command: 'Sample Standard Deviation" and “Population Standard Deviation” - but if I try to insert a set of numbers separated by commas it always says “too many arguments”. </p>
<p>d) What exactly is meant by transposing matrices?</p>
<p>e) If I try to solve any form of linear, quadratic or exponential form of regression, do I have to order the data by their value when I type it in in my calculator?</p>
<p>f) When do I know when to use radians or degrees?</p>
<p>I am usually working with my scientific calculator in degree mode and I found this question in Barron’s:</p>
<p>If f(x) = e^x and g(x) = sin x, then the value of f[g(2^(1/2))] is?
a) -0.01
b) -0.8
c) 0.34
d) 1.8
e) 2.7</p>
<p>So I solved this equation and noticed that my answer was not matching any of the answer choices and so I changed to radians and the answer was E. But why do I have to use radian mode here? Maybe next time they also offer the answer choice if I use degree mode and then I am screwed ;).</p>
<p>Thanks for your help!</p>