Question

In: Advanced Math

(1) Recall on February 6 in class we discussed e 0 + e 2πi/n + e...

(1) Recall on February 6 in class we discussed e 0 + e 2πi/n + e 4πi/n + · · · + e 2(n−1)πi/n = 0 and in order to explain why it was true we needed to show that the sum of the real parts equals 0 and the sum of the imaginary parts is equal to 0.

(a) In class I showed the following identity for n even using the fact that sin(2π − x) = − sin(x): sin(0) + sin(2π/n) + sin(4π/n) + · · · + sin(2(n − 1)π/n) = 0 Do the same thing for n odd (make sure it is clear, at least to yourself, why the argument is slightly different for n even and n odd).

(b) Using the identity cos(x) = − cos(x + π), show that cos(0) + cos(2π/n) + cos(4π/n) + · · · + cos(2(n − 1)π/n) = 0 for n even.

(c) Why does the same proof not work for n odd ? Show and explain what goes wrong for the example of n = 3.

Solutions

Expert Solution


Related Solutions

Recall the dynamic programming algorithm we saw in class for solving the 0/1 knapsack problem for...
Recall the dynamic programming algorithm we saw in class for solving the 0/1 knapsack problem for n objects with a knapsack capacity of K. In particular, we characterized our recurrence OPT(j, W) to be following quantity: OPT(j, W) := The maximum profit that can be obtained when selecting from objects 1, 2, . . . , j with a knapsack capacity of W , where (after filling in our dynamic programming table), we return the value stored at OPT(n, K)...
Recall that a sequence an is Cauchy if, given ε > 0, there is an N...
Recall that a sequence an is Cauchy if, given ε > 0, there is an N such that whenever m, n > N, |am − an| < ε. Prove that every Cauchy sequence of real numbers converges.
Recall that we discussed the concept of the Global Minimum Variance Portfolio in one of the...
Recall that we discussed the concept of the Global Minimum Variance Portfolio in one of the lectures and defined it as that portfolio on the efficient frontier that has the least risk.​ Now, consider a portfolio with only two​ assets, asset​ X, and asset Y. The returns of these assets are uncorrelated with each other. Asset X has a volatility of​ 9%, and asset​ Y’s volatility is​ 16%. What will be the weight of asset X in a minimum variance...
12. (a) Is the subset { (e,0), (e,6), (e,12), (h,0), (h,6), (h,12) }, a subgroup of...
12. (a) Is the subset { (e,0), (e,6), (e,12), (h,0), (h,6), (h,12) }, a subgroup of the direct product group ( V x Z18 )? (V is the Klein four group.) Carefully explain or justify your answer. (b) Is the subgroup { (e,0), (e,6), (e,12), (h,0), (h,6), (h,12) }, a normal subgroup of the direct product group ( V x Z18 )? Carefully explain or justify your answer.
6. In class we discussed autosomal polymorphisms such as widow’s peak and detached ear lobes, both...
6. In class we discussed autosomal polymorphisms such as widow’s peak and detached ear lobes, both of which are dominant traits. Suppose that a man with a widow’s peak and attached ear lobes (whose father had detached ear lobes) marries a woman without a widow’s peak and detached ear lobes (whose father had attached ear lobes). What is the probability that their first child will: a.not have a widow’s peak or attached ear lobes? b.have both a widow’s peak and...
Hotelling’s location game. Recall the voting game discussed in class. There are two candidates, each of...
Hotelling’s location game. Recall the voting game discussed in class. There are two candidates, each of whom chooses a position from the set S = (1,2,...10). The voters are equally distributed across these ten positions. Voters vote for the candidate whose position is closest to theirs. If the two candidates are equidistant from a given position, the voters at that position split their votes equally. First, unlike in the game analyzed in class, assume that both candidates only care about...
1. Based on the hormones we have discussed in class, create a list of hormones that...
1. Based on the hormones we have discussed in class, create a list of hormones that play a role in the following areas: increased CHO utilization, increased PRO synthesis, increased lipid breakdown/FFA utilization. 2. Explain the two ways in which plasma volume and osmolality are regulated during exercise. Be sure to define all key terms.
   \(\int_{0}^{\pi}e^xsinx dx\) with n=6 subdivisions 1) Find the exact value of the integral 2) Approximate...
   \(\int_{0}^{\pi}e^xsinx dx\) with n=6 subdivisions 1) Find the exact value of the integral 2) Approximate the integral using the trapezoidal rule, midpoint rule and simpson rule. 3) Find the errors using each of these rules 4) For each of these rules, show how large n should be, to be within .0001 of the actual answer.
1- In class, we discussed the MACRS system for tax depreciation and special elections available to...
1- In class, we discussed the MACRS system for tax depreciation and special elections available to taxpayers. Explain the MACRS system, the elections available to the taxpayer, and why (why not) a taxpayer would choose to make an election in regards to tax depreciation.   Be sure to include what types of assets qualify for each election.
In class, we discussed the fact that “Mortgages are bonds and bonds are mortgages”. Thus, we...
In class, we discussed the fact that “Mortgages are bonds and bonds are mortgages”. Thus, we can use the basics of bond pricing and yield to maturity to evaluate across lending options in mortgages. Assume you have two mortgage home loans to choose from: a. $400,000 @ 4.5% (with monthly compounding) for 30 years with $20,000 in finance fees (aka: points) b. $400,000 @ 6.5% (with monthly compounding) for 15 years with no finance fees (aka: points) Further assume both...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT