C++ cmath exp() Function

The C++ cmath exp() function computes the exponential value of a number, returning the result as a floating-point value. It calculates e to the power of x. where (e is the base of natural logarithms) approximately 2.718.

This function is particularly useful for calculating exponential growth and financial applications and other cases, where the value of e raised to a specific power (e^x) is required.

Syntax

Following is the syntax for C++ cmath exp() function.

double exp(double x);
or
float exp(float x);
or
long double exp(long double x);

Parameters

• x - The value of the exponent.

Return Value

The function returns e raised to the power of x, as a floating-point value. If the magnitude of the result is too large to represent, the function returns HUGE_VAL (or HUGE_VALF or HUGE_VALL) with the correct sign, indicating an overflow error.

Time Complexity

The time complexity of this function is constant, i.e.,O(1).

Example 1

In the following example, we are going to calculate the exponential of 1, which means finding the value of e (Euler's number) raised to the power of 1.

#include <iostream>
#include <cmath>
int main() {
   double x = 1.0;
   std::cout << "exp(" << x << ") = " << std::exp(x) << std::endl;
   return 0;
}

Output

Output of the above code is as follows

exp(1) = 2.71828

Example 2

In the following example, we're going to use exp() function to calculate the exponential of a negative number.

#include <iostream>
#include <cmath>
int main() {
   double value = -1.0;
   double result = exp(value);
   std::cout << "The exponential of " << value << " is " << result << std::endl;
   return 0;
}

Output

Following is the output of the above code

The exponential of -1 is 0.367879

Example 3

Let's Calculate Exponential for a Fractional value by using exp() function.

#include <iostream>
#include <cmath>
int main() {
   double x = 0.8;
   std::cout << "exp(" << x << ") = " << std::exp(x) << std::endl;
   return 0;
}

Output

If we run the above code it will generate the following output

exp(0.8) = 2.22554