Phonon
• Member for 10 years, 10 months
• Last seen more than 2 years ago
• Los Angeles, CA

It's Pythagorean theorem, just like with 2D space. $||[0, 0, 0]-[1, 2, 3]|| = \sqrt{(0-1)^2+(0-2)^2+(0-3)^2} = \sqrt{1+4+9} = \sqrt{14}$

Break the integral up into a sum of integrals over intervals of length 1. This way the floor of $x$ becomes constant for that interval. You get $$\int_0^\infty = \sum_{k=0}^{\infty}k\left(\int_k^{k+1}... View answer 3 votes Yes, this is always true... sorrrrt of, given that a and b are of the same length, but you must be careful! In (b^T * a) * r, the last multiplication is that of a scalar by a matrix (a vector ... View answer 2 votes Assuming factory workers usually belong to unions, we should assume that they work exactly 40 hours per week. Assuming the current state of the economy, the answer in fact approaches 0, but that's for ... View answer 1 votes Hint: The fact that \vec{a} \times \vec{b} = \vec{c} \times \vec{d} means that \vec{a} and \vec{b} lie in the same plane as \vec{c} and \vec{d}. What does this tell you about a ... View answer 0 votes The original question was asking about How many ways 12 persons may be divided *into three groups of 4 persons each*?. That's not the same as how many possible groups of 4 people can be formed from 12.... View answer 0 votes Well, you have 3 equations and 5 unknowns. With algebraic manipulations (by substituting for A and then for B) you can get it to the form$$-X^TX + I + XC + D = 0. This way you're left with one ...