(6 points) let s = {1,2,3,4,5} (a) list all the 3-permutations of s. (b) list all the 5-permutations of s.

A diagonal matrix can only be orthogonal if all of its diagonal entries are either 1 or -1.

For a matrix to be orthogonal, it must satisfy the condition that its transpose is equal to its inverse. For a diagonal matrix, the transpose is simply the matrix itself, since all off-diagonal entries are zero. Therefore, for a diagonal matrix to be orthogonal, its inverse must also be equal to itself. This means that the diagonal entries must be either 1 or -1, since those are the only values that are their own inverses. Any other diagonal entry would result in a different value when its inverse is taken, and thus the matrix would not be orthogonal. It's worth noting that not all diagonal matrices are orthogonal. For example, a diagonal matrix with all positive diagonal entries would not be orthogonal, since its inverse would have different diagonal entries. The only way for a diagonal matrix to be orthogonal is if all of its diagonal entries are either 1 or -1.

Learn more about orthogonal here

https://brainly.com/question/30772550

#SPJ11

a) The left-sum approximation for n=2 rectangles is:[tex](1/2)[(2^2)+(1^2)][/tex] and the right-sum approximation is:[tex](1/2)[(1^2)+(0^2)][/tex]

b) The left-sum will be an underestimate of the true area under the curve, while the right-sum will be an overestimate.

c) Evaluating the left-sum approximation gives 1.5, while the right-sum approximation gives 0.5.

d) The left-sum approximation for n=4 rectangles is:[tex](1/4)[(2^2)+(5/4)^2+(1^2)+(1/4)^2],[/tex] and the right-sum approximation is: [tex](1/4)[(1/4)^2+(1/2)^2+(3/4)^2+(1^2)].[/tex]

(a) The integral is:

[tex]\int (from 1 to 2) t^2 dt[/tex]

(b) Using n = 2 rectangles, the width of each rectangle is:

Δt = (2 - 1) / 2 = 0.5

The left-sum approximation is:

[tex]f(1)\Delta t + f(1.5)\Delta t = 1^2(0.5) + 1.5^2(0.5) = 1.25[/tex]

The right-sum approximation is:

[tex]f(1.5)\Delta t + f(2)\Deltat = 1.5^2(0.5) + 2^2(0.5) = 2.25[/tex]

(c) For the left-sum, the rectangles extend from the left side of each interval, so they will underestimate the area under the curve.

For the right-sum, the rectangles extend from the right side of each interval, so they will overestimate the area under the curve.

Using a calculator, we get:

∫(from 1 to 2) t^2 dt ≈ 7/3 = 2.3333

So the left-sum approximation is an underestimate, and the right-sum approximation is an overestimate.

(d) Using n = 4 rectangles, the width of each rectangle is:

Δt = (2 - 1) / 4 = 0.25

The left-sum approximation is:

[tex]f(1)\Delta t + f(1.25)\Delta t + f(1.5)\Delta t + f(1.75)\Delta t = 1^2(0.25) + 1.25^2(0.25) + 1.5^2(0.25) + 1.75^2(0.25) = 1.5625[/tex]The right-sum approximation is:

[tex]f(1.25)\Delta t + f(1.5)\Delta t + f(1.75)\Delta t + f(2)Δt = 1.25^2(0.25) + 1.5^2(0.25) + 1.75^2(0.25) + 2^2(0.25) = 2.0625.[/tex]

Using a calculator, we get:

[tex]\int (from 1 to 2) t^2 dt \approx 7/3 = 2.3333[/tex]

So the left-sum approximation is still an underestimate, but it is closer to the true value than the previous approximation.

The right-sum approximation is still an overestimate, but it is also closer to the true value than the previous approximation.

For similar question on rectangles.

https://brainly.com/question/27035529

#SPJ11