math.h

Question 1

What is pow()?

Declaration:

double pow(double x, double y);

Answer 1

Returns x raised to the power of y.

Range:

x cannot be negative if y is a fractional value. x cannot be zero if y is less than or equal to zero.

Question 2

What is tanh()?

Declaration:

double tanh(double x);

Answer 2

Returns the hyperbolic tangent of x.

Range:

The value of x has no range. The returned value is in the range of -1 to +1 (inclusive).

Question 3

What is log10()?

Declaration:

double log10(double x);

Answer 3

Returns the common logarithm (base-10 logarithm) of x.

Range:

There is no range limit on the argument or return value.

Question 4

What is atan2()?

Declaration:

double atan2(doubly y, double x);

Answer 4

Returns the arc tangent in radians of y/x based on the signs of both values to determine the correct quadrant.

Range:

Both y and x cannot be zero. The returned value is in the range of -p/2 to +p/2 (inclusive).

Question 5

What is modf()?

Declaration:

double modf(double x, double *integer);

Answer 5

Breaks the floating-point number x into integer and fraction components.
The returned value is the fraction component (part after the decimal), and sets integer to the integer component.

Range:

There is no range limit on the argument or return value.

Question 6

What is asin()?

Declaration:

double asin(double x);

Answer 6

Returns the arc sine of x in radians.

Range:

The value of x must be within the range of -1 to +1 (inclusive). The returned value is in the range of -p/2 to +p/2 (inclusive).

Question 7

What is ldexp()?

Declaration:

double ldexp(double x, int exponent);

Answer 7

Returns x multiplied by 2 raised to the power of exponent.
x*2^exponent

Range:

There is no range limit on the argument or return value.

Question 8

What is atan()?

Declaration:

double atan(double x);

Answer 8

Returns the arc tangent of x in radians.

Range:

The value of x has no range. The returned value is in the range of -p/2 to +p/2 (inclusive).

Question 9

What is sqrt()?

Declaration:

double sqrt(double x);

Answer 9

Returns the square root of x.

Range:

The argument cannot be negative. The returned value is always positive.

Question 10

What is cosh()?

Declaration:

double cosh(double x);

Answer 10

Returns the hyperbolic cosine of x.

Range:

There is no range limit on the argument or return value.

Question 11

What is frexp()?

Declaration:

double frexp(double x, int *exponent);

Answer 11

The floating-point number x is broken up into a mantissa and exponent.
The returned value is the mantissa and the integer pointed to by exponent is the exponent. The resultant value is x=mantissa * 2^exponent.

Range:

The mantissa is in the range of .5 (inclusive) to 1 (exclusive).

Question 12

What is acos()?

Declaration:

double acos(double x);

Answer 12

Returns the arc cosine of x in radians.

Range:

The value x must be within the range of -1 to +1 (inclusive). The returned value is in the range of 0 to pi (inclusive).

Question 13

What is sinh()?

Declaration:

double sinh(double x);

Answer 13

Returns the hyperbolic sine of x.

Range:

There is no range limit on the argument or return value.

Question 14

What is fmod()?

Declaration:

double fmod(double x, double y);

Answer 14

Returns the remainder of x divided by y.

Range:

There is no range limit on the return value. If y is zero, then either a range error will occur or the function will return zero (implementation-defined).

Question 15

What is cos()?

Declaration:

double cos(double x);

Answer 15

Returns the cosine of a radian angle x.

Range:

The value of x has no range. The returned value is in the range of -1 to +1 (inclusive).

Question 16

What is exp()?

Declaration:

double exp(double x);

Answer 16

Returns the value of e raised to the xth power.

Range:

There is no range limit on the argument or return value.

Question 17

What is fabs()?

Declaration:

double fabs(double x);

Answer 17

Returns the absolute value of x (a negative value becomes positive, positive value is unchanged).

Range:

There is no range limit on the argument. The return value is always positive.

Question 18

What is floor()?

Declaration:

double floor(double x);

Answer 18

Returns the largest integer value less than or equal to x.

Range:

There is no range limit on the argument or return value.

Question 19

What is HUGE_VAL?

Answer 19

A constant.

A function returns this value when the result of a mathematical operation yields a value that is so large in magnitude that it is not representable with its return type. This is one of the possible range errors, and is signaled by setting errno to ERANGE.

Actually, functions can either return a positive or a negative HUGE_VAL (HUGE_VAL or -HUGE_VAL) to at least indicate the sign of the result.

Question 20

What is log()?

Declaration:

double log(double x);

Answer 20

Returns the natural logarithm (base-e logarithm) of x.

Range:

There is no range limit on the argument or return value.

Question 21

What is sin()?

Declaration:

double sin(double x);

Answer 21

Returns the sine of a radian angle x.

Range:

The value of x has no range. The returned value is in the range of -1 to +1 (inclusive).

Question 22

What is tan()?

Declaration:

double tan(double x);

Answer 22

Returns the tangent of a radian angle x.

Range:

There is no range limit on the argument or return value.

Question 23

What is ceil()?

Declaration:

double ceil(double x);

Answer 23

Returns the smallest integer value greater than or equal to x.

Range:

There is no range limit on the argument or return value.