C++ Math

#include <iostream>
#include <cmath>

void mathFunc()
{
    double weight{7.7};

    // floor
    std::cout << "Weight rounded to floor is : " << std::floor(weight) << std::endl;

    // ceil
    std::cout << "Weight rounded to ceil is : " << std::ceil(weight) << std::endl;

    // abs
    double savings{-5000};

    std::cout << "Abs of weight is : " << std::abs(weight) << std::endl;
    std::cout << "Abs of savings is : " << std::abs(savings) << std::endl;

    // exp : f(x) = e ^ x , where e = 2.71828 . Test the result here against a calculator
    double exponential = std::exp(10);
    std::cout << "The exponential of 10 is : " << exponential << std::endl;

    // pow
    std::cout << "3 ^ 4 is : " << std::pow(3, 4) << std::endl;
    std::cout << "9^3 is : " << std::pow(9, 3) << std::endl;

    // log : reverse function of pow. if 2^3 = 8 , log 8 in base 2 = 3.  Log is like asking
    //  to which exponent should we elevate 2 to get eight ? Log, by default computes the log
    //  in base e. There also is another function which uses base 10 called log10

    // Try the reverse operation of  e^4 = 54.59 , it will be log 54.59 in base e = ?
    std::cout << "Log ; to get 54.59, you would elevate e to the power of : "
              << std::log(54.59) << std::endl;

    // log10 , 10 ^ 4 = 10000  , to get 10k , you'd need to elevate 10 to the power of ? , this is log in base 10
    std::cout << "To get 10000, you'd need to elevate 10 to the power of : "
              << std::log10(10000) << std::endl; // 4

    // sqrt
    std::cout << "The square root of 81 is : " << std::sqrt(81) << std::endl;

    // round. Halfway points are rounded away from 0. 2,5 is rounded to 5 for example
    std::cout << "3.654 rounded to : " << std::round(3.654) << std::endl;
    std::cout << "2.5 is rounded to : " << std::round(2.5) << std::endl;
    std::cout << "2.4 is rounded to : " << std::round(2.4) << std::endl;
}

int main()
{
    mathFunc();
    return 0;
}