##### Synopsis

    #include <math.h>
    double hypot(double x, double y);

##### Description

hypot compute the square root of the sum of the squares of x and y, sqrt(x*x + y*y), without undue overflow or underflow. If x and y are the lengths of the sides of a right-angled triangle, then hypot computes the length of the hypotenuse..

##### IEC 60559 math library behavior

If x or y is +? or -?, hypot returns ?.
If x or y is NaN, hypot returns NaN.

##### Portability

hypot conforms to ISO/IEC 9899:1999 (C99).