Functions

Question

what functions that we have to learn when we get older?

Answer

The functions that you will need to understand when you get older will depend strongly on what sort of work you end up doing when you graduate. But I can tell you what types of functions you will need to learn in school to succeed in your math courses: 1. Polynomials, especially including linear functions: A polynomial is a function like f(x) = 4x^5 + 4x^2 - x + 11, where you have a variable (in this case, x) raised to various powers, multiplied by various numbers (called coefficients), and all these terms are added or subtracted to one another. A linear function is a polynomial that only has multiples of x (to the first power), and constant terms. For example, f(x) = 3x+9 is a linear function. 2. Rational functions, which are just ratios of polynomials. For example, f(x) = 4x^2 - 14 is a rational function. ------------- 3x^3 - x + 3 3. Trigonometric functions, such as f(x) = sin x (which are much harder to explain) 4. Exponential functions, where there is a constant as the base of the exponent, and the variable x is in the exponent itself. For example, f(x) = 3^x is an exponential function. Note that this is different from polynomials, where it's the variable in the base and the constant in the exponent. These are the main categories. Many other functions can be made by combining the pieces I've described above, such as f(x) = sin(x^3 - 2) - 5^(cos x) + 11x - 9 --------- 2^x I hope that helped! Diane