6. write a user-defined matlab function for the following math function: r() = 4cos(4sin ) the input to the function is  (in radians) and the output is r. write the function such that  can be a vector. a) use the function to calculate r(/6) and r(5/6). b) use the function to plot (polar plot) r() for 0 ≤  ≤ 2. hint: use “ polar” and/or for “polar plot in matlab." include the title “'r(\theta)=4cos(4sin(\theta))”

Assume the existence of a bankaccount class. define a derived class, savingsaccount that contains two instance variables: the first a double, named interestrate, and the second an integer named interesttype. the value of the interesttype variable can be 1 for simple interest and 2 for compound interest. there is also a constructor that accepts two parameters: a double that is used to initialize the interestrate variable, and a string that you may assume will contain either "simple", or "compound", and which should be used to initialize the interesttype variable appropriately. there should also be a pair of functions getinterestrate and getinteresttype that return the values of the corresponding data members (as double and int respectively).