The calculators on this site are all intuitive to use. You may benefit from getting deeper insight by familiarising yourself to the details on how to use these calculators more effectively as follows.
Use +, , *, / and ^ for addition, subtraction, multiplication, division, and power, respectively. The use of * is optional for multiplication (unless you are multiplying literal numbers, of course). Use parentheses () for grouping.
The calculators on this site are programmed to understand expressions such as 3+2, 2*tan(pi/3), x2, x/2, x*sin(x) which would otherwise be entered, rather tediously, as 3+(2), 2*(tan(pi/3)), x((2)), x/(2), x*(sin(x)) With these Calculators it is not necessary to use the excessive parentheses. These artificial intelligent Calculators make it possible to type in expressions with minimal effort and if you make a syntax error they will give you a precise error message highlighting the error.
Furthermore, the Calculators on this site distinguish binary from unary  sign and ignores redundant unary  signs. That is 1x+2*x is understood by them and is replaced internally by 1  x + 2*x
When entering a formula containing numerators and denominators, or exponents (powers or radicals) make sure you enclose them with parentheses (it is always safe to do so even though in some instances it may not be necessary).
For example, the expression
4x3x + 2 
2x 
is entered as (4x^(3x)+2)/(2x)
In addition to algebraic functions such as linear, quadratic and other polynomial and rational functions, you can use any of these predefined functions in your expressions. This includes power functions, logarithmic and exponential functions. You can also graph piecewise defined functions and special step functions such as floor and ceil and round. In addition, you can graph trigonometric, and hyperbolic functions and their inverses. You can also use mathematical constants such as the number represented by e (= 2.718..., Euler's number, Natural Logarithm base) and the number π (3.14... ) in expressions.
Expression  Type in  

2(3)(4)  2(3)(4) or 2*34  
x^{2}  x^2 (or xx)  
x^{2}  x^2 (or xx)  
x^{2}  x^2  
(x^{3})^{2}  (x^3)^2 or x^3^2  

4x^2/3  

(x+2)/(3x)  
e^{x} + e^{x}  e^x + e^x  
e^{4x} + e^{4x}  e^(4x)+ e^(4x)  
3^{4x}  3^(4x)  
x  abs(x)  
6x7  abs(6x7)  
√x  sqrt(x) or x^(1/2)  
√2x+3  sqrt(2x+3) or (2x+3)^.5  
^{3}√x  x^(1/3)  
x^{3}y  x^3y  
x^{3y}  x^(3y)  
sin(2πx)  sin(2pix)  
{(1,2),(3,4)}  1,2; 3,4 