# Tutor profile: Jose R.

## Questions

### Subject: SQL Programming

Apply the TRANSLATION, CLEANUP and SQL steps for the design of the following sql query “Provide a list of all staff ids, staff first name, staff last name, and salaries from the staff table.”

TRANSLATION: SELECT FROM THE STAFF TABLE A LIST WITH THE IDENTIFIER OF EACH STAFF, THE FIRST NAME, LAST NAME AND SALARY. CLEANUP: SELECT STAFF IDENTIFIER STAFF, FIRST NAME, LAST NAME SALARY. SQL: Select StaffID,StfFirstName,StflastName,Salary from staff;

### Subject: MATLAB

To make a function that allows to construct in a symbolic way the polynomial of interpolation of degree n by the method of lagrange

function a = polylagSym (xi, yi) % Input - xi is the vector of abscissa 1 x n % - yi is the vector of ordinates 1 x n % Output - a is the vector 1 x n, vector containing the coefficients of % Lagrange polynomial of degree N-1 % of the form a1x ^ (n-1) + a2X ^ (n-2) + .... + a (n-1) X + a (n); % INTERPOLATION "LAGRAGE POLYNOMY" n=length(xi); syms pn x=sym('x');% this function allows us to leave the variable 'x' as symbolic % and thus be able to work with it, without having to assign a value to it. for j=1:n product=1; for i=1:j-1 product=product*(x-xi(i)); % Calculation of the top 1 product of L end product2=1; for i=j+1:n product2=product2*(x-xi(i));% Calculation of the top 2 product of L end product3=1; for i=1:j-1 product3=product3*(xi(j)-xi(i)); % calculation of the lower product 1 of L end product4=1; for i=j+1:n product4=product4*(xi(j)-xi(i)); %calculation of the lower product 2 of L end % Calculation of lagrange polynomials L(j)=(product*product2)/(product3*product4); end %Calculation of the interpolating polynomial of lagrange pn=0; for j=1:n pn=pn+L(j)*yi(j); end pn = simple(pn);

### Subject: Numerical Analysis

Can Adams variable step multistep methods be improved for the solution of ordinary differential equations? Effectively, the time can be improved by the previous calculation of coefficients for quotient ratios of predetermined steps. See the next research article:

Effectively, the time can be improved by the previous calculation of coefficients for quotient ratios of predetermined steps. See the following research article of my doctoral thesis https://www.hindawi.com/journals/mpe/2010/765620/

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