C++ cmath pow()Function

The C++ cmath pow() is used to compute the result of raising a base number (x) to the power of an exponent (y). It can accept various types of numeric inputs, such as integers, floats, or doubles, and will return a floating-point value that represents the calculated result.

Additionally, std::pow() handles both positive and negative exponents, enabling calculations for roots and reciprocal values.

Syntax

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

double pow(double x, double y);
or
float pow(float x, float y);
or
long double pow(long double x, long double y);

Parameters

• x- The base value, which is the number to be raised.

• y- The exponent value.

Return Value

The function returns a floating-point value representing x^y

Time Complexity

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

Example 1

The following example shows the basic usage of the pow(x,y) function by passing base and exponent values.

#include <iostream>
#include <cmath>
int main() {
   double base = 2.0;
   double exponent = 3.0;
   double result = std::pow(base, exponent);
   std::cout << "2 raised to the power 3 is: " << result << std::endl;
   return 0;
}

Output

Output of the above code is as follows

2 raised to the power 3 is: 8

Example 2

In the following, we are going to find square roots and other fractional roots without directly using a square root function.

#include <iostream>
#include <cmath>
int main() {
   double base = 9.0;
   double exponent = 0.5;
   double result = std::pow(base, exponent);
   std::cout << "Square root of 9 is: " << result << std::endl;
   return 0;
}

Output

Following is the output of the above code

Square root of 9 is: 3

Example 3

In this example, raising a negative base to an even power results in a positive number. This occurs because multiplying an even number of negative values produces a positive outcome.

#include <iostream>
#include <cmath>
int main() {
   double base = -2.0;
   double exponent = 4.0;
   double result = std::pow(base, exponent);
   std::cout << "-2 raised to the power 4 is: " << result << std::endl;
   return 0;
}

Output

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

-2 raised to the power 4 is: 16