a) it is desired to find two positive numbers whose sum equal 16 and whose product is to be a large as possible b) The product of two positive...

whose product is to be a large as possibleb) The product of two positive numbers equals 16. Find the numbers if twice the first plus three times the second is to be as small as possible.c) Calculate the derivative of function y(t): y(t)=e^[(1+x^2)/(1-x^2)]