Rules for Entering Functions 
You don't need to write the multiplication sign between a number and a variable (parentheses, function). 
Function  It is possible to write 
4 * x  4x 
2 * (x+1)  2(x+1) 
If the argument of a function is x, 2x, 3x, and so on then you don't need to write the parentheses. 
Function  It is possible to write 
sin(2*x)  sin2x 
tg(4*x)  tg4x 
In any other case, the function argument must be written in parentheses. 
Function  You must write 
sin(x/4)  sin(x/4) 
tg(2x+pi/4)  tg(2x+pi/4) 
You don't need to write the multiplication sign between a parentheses and a functions. 
Function  It is possible to write 
2 * (x+1) * (x2)  2(x+1)(x2) 
3 * (x2) * cos^{2}(x+pi)  3(x2) cos(x+pi)**2 
4 * sin(2*x) * cos(x+pi)^{2}  4sin2x cos((x+pi)**2) 
The decimal fraction must be written using a dot. For example: 0.5 
If you want to exponentiate m/n where n is odd, then you cannot use exponentiation. 
You cannot use  You must use 
x **(1/3)  root(3,x) 
x **(2/3)  root(3,x**2) 
Designations

+  / *  addition, subtraction, division and multiplication 
** or ^  exponentiation 
root (n,x)  root of nth degree. n = 2, 3, 4, 5 and so on. 
pi  pi 
sin (x)  sine of x 
cos (x)  cosine of x 
tan (x)  tangent of x 
cot (x)  cotangent of x 
ln (x)  natural logarithm 
lg (x)  decimal logarithm 
log (n,x)  log_{n}x n > 0 n ≠ 1 
exp (x)  e^{x} 
asin (x)  arcsine of x 
acos (x)  arccosine of x 
atan (x)  arctangent of x 
acot (x)  arccotangent of x 
abs (x)  x 
If you want to draw a parametric graph the variable t is used instead of the variable x. 
Please select t range not more than 200 pi. 