# Elementary function which we should know for basic Maths for 12th Grade

We have learnt the following function from our online tutor

Elementary functions:

Constant function: y=c where c is a constant, defined for all real x.

Power function: y=x^α, where α is a positive integer. The function is defined in the infinite interval -∞<x<∞. α is a negative integer. The function is defined for all values of x except for x=0.

General exponential function: y=a^x, where a is positive not equal to unity. This function is defined for all values of x.

Logarithmic function: y=logx, a>but a is not equal to 1. This function is defined for all x>0.

Trigonometric function: y=sinx, y=cozx defined for all real x.

Y=tanx, y=secx, defined for R-(2n+1) ∏/2

Y=cotx, y=cosecx, defined for R-n∏, where n€1

It must be noted that in all these function the variable x is expresses in radians. All these functions have a very important property that is periodicity.

Limit of a function

Let y=f(x) be a function of x. If at x=a, f(x) takes indeterminate form, then we consider the values of the function which are very near to ‘a’. If these values tend to a definite unique number as x tends to ‘a’, then the unique number so obtained is called the limit of f(x) at x=a.