# FAQ - Math

**Q:** What can I do with a degree in math?**A:** As you know, many students major in mathematics because they want to become math
teachers, either at a high school level or at the college or university level. What
yo may not know is that SJSU math alumni also work in industries ranging from aviation
safety to risk management to financial planning to satellite design. In fact, one
of the three co-founders of Oracle, Edward Oates (**http//www.oracle.com/innovation/innovator-edward-oates.html**), graduated from SJSU with a BA Math degree. You will find more information on math
careers the MAA webstie, http://www.maa.org/careers/.

**Q**: Are there any requirements if I want to change my major to math?**A:** Yes. If you are interested in changing your major to math, please fill out the online
"Contact Us" form and request to see an advisor. After you have talked to an advisor,
you need to fill out the change of major form found at the registrar's website and
get department approval form Dr. Blockus.

Please note, the requirements to change your major to math are as follows:

- Grade of C- or better in Calculus I (Math 30 or Math 30P) or AP credit for Calculus I;
- Grade of C- or better in Discrete Math (Math 42);
- GPA of 2.0 or higher in all mathematics courses taken, Precalculus (Math 19) and above.

All transfer students or students wanting to change their major to a BA Math or BS Applied Math degree who have 60+ units will be required to have completed Math 30, 31, 32, and 42 with a grade of C- or better in each course (where Math 32 and 42 could be replaced with any other approved upper division course such as Math 129A, 133A, 161A etc.). These students will also be required to have an overall GPA of at least 2.0 in all math courses taken, Precalculus (Math 19) and above.

**Q:** What do discrete and continuous math mean?**A:** Discrete mathematics deals with the mathematics of countable things. A countable
set is one whose elements can be put in on-to-one correspondence with the positive
integers. They can be counted - hence the term countable. Finite sets are countable.
For example, if you are dealing with a variable, say X, which takes on the values
of the positive even integers {2, 4, 6, 8, . . . . } then it is a discrete variable.
However, if your variable X can take on any value between 0 and 1, then it is considered
a continuous variable. They are related but not the same. Why don't you "google" it
to see what others have to say about it.

**Q:** What is pure and applied mathematics?**A:** Pure mathematics generally refers to the study of mathematics for its own sake without
any regard to its applications. It is generally associated with rigor and abstraction
and in some sense, it can be considered art. Mathematics can be beautiful and exquisite,
just like a painting. Examples of areas which are usually considered pure mathematics
are abstract algebra, topology, and number theory. But each of these areas have been
applied to real world problems. Lie Algebras are used in physics, knot theory is being
applied to protein folding, and number theory is used in cryptography. Unlike art,
beautiful mathematics can be useful.

Applied mathematics is motivated by real world problems. It still requires rigor and abstraction. There are still theorems to be proven, algorithms to be developed and evaluated, errors to be estimated. Examples of areas of applied mathematics are differential equations, numerical analysis, operation research, statistics, actuarial science. Differential equations is sometimes referred to as the mathematical language of science and engineering because many laws and principles of science can be expressed as a differential equation. For example, in calculus you learn that Newton's second law, F = ma, as applied to a free falling object, can be written as a differential equation, x"(t)=-g.

But applied mathematics is not as simple as "plugging it in". In high school, you learned how to solve a system of 2 linear equations with 2 unknowns. What if you have 1,000,000 equations and 1,000,000 unknowns? Can you still use the same method? Assuming there is a solution to the problem, the answer is "Sure. Why not?". You can use a method called Gaussian elimination to find the answer to the system of equations. Yes, in theory, you can do that. We talking about 1,000,001,000,000 coefficients. That's a LOT of numbers to remember. And it would require 1,000,000,999,996,500,002 arithmetic operations (How long are you willing to work on this?) And if you use a computer, there are other issues like memory, efficiency, accuracy, and stability. The problem of solving a large or ill-behaved system of equations comes up in so many applications that we offer an entire course on the subject, Math 143M.