int abs(int i) 返回整型參數(shù)i的絕對(duì)值
double cabs(struct complex znum) 返回復(fù)數(shù)znum的絕對(duì)值
double fabs(double x) 返回雙精度參數(shù)x的絕對(duì)值
long labs(long n) 返回長(zhǎng)整型參數(shù)n的絕對(duì)值
double exp(double x) 返回指數(shù)函數(shù)e^x的值
double frexp(double value,int *eptr) 返回value=x*2^n中x的值(0.5<=x<1),n存貯在eptr中
double ldexp(double value,int exp); 返回value*2^exp的值
double log(double X) 返回logeX的值,以e為底的對(duì)數(shù)
double log10(double x) 返回log10x的值,以10為底的對(duì)數(shù)
double pow(double x,double y) 返回x^y的值
double pow10(int p) 返回10^p的值
double sqrt(double x) 返回a,且a滿足a*a=x,a>=0
double acos(double x) 返回x的反余弦cos^-1(x)值,x為弧度
double asin(double x) 返回x的反正弦sin^-1(x)值,x為弧度
double atan(double x) 返回x的反正切tan^-1(x)值,x為弧度
double atan2(double y,double x) 返回y/x的反正切tan^-1(x)值,y的x為弧度
double cos(double x) 返回x的余弦cos(x)值,x為弧度
double sin(double x) 返回x的正弦sin(x)值,x為弧度
double tan(double x) 返回x的正切tan(x)值,x為弧度
double cosh(double x) 返回x的雙曲余弦cosh(x)值,x為弧度
double sinh(double x) 返回x的雙曲正弦sinh(x)值,x為弧度
double tanh(double x) 返回x的雙曲正切tanh(x)值,x為弧度
double hypot(double x,double y) 返回直角三角形斜邊的長(zhǎng)度(z),x和y為直角邊的長(zhǎng)度,z^2=x^2+y^2
double ceil(double x) 返回不小于x的最小整數(shù)
double floor(double x) 返回不大于x的最大整數(shù)
void srand(unsigned seed) 初始化隨機(jī)數(shù)發(fā)生器
int rand() 產(chǎn)生一個(gè)隨機(jī)數(shù)并返回這個(gè)數(shù)
double poly(double x,int n,double c[])從參數(shù)產(chǎn)生一個(gè)多項(xiàng)式
double modf(double value,double *iptr)將雙精度數(shù)value分解成整數(shù)部分和小數(shù)部分，iptr為整數(shù)部分，返回小數(shù)部分
double fmod(double x,double y) 返回x/y的余數(shù)
double atof(char *nptr) 將字符串nptr轉(zhuǎn)換成浮點(diǎn)數(shù)并返回這個(gè)浮點(diǎn)數(shù)
double atoi(char *nptr) 將字符串nptr轉(zhuǎn)換成整數(shù)并返回這個(gè)整數(shù)
double atol(char *nptr) 將字符串nptr轉(zhuǎn)換成長(zhǎng)整數(shù)并返回這個(gè)整數(shù)
char *ecvt(double value,int ndigit,int *decpt,int *sign)將浮點(diǎn)數(shù)value轉(zhuǎn)換成字符串并返回該字符串
char *fcvt(double value,int ndigit,int *decpt,int *sign)將浮點(diǎn)數(shù)value轉(zhuǎn)換成字符串并返回該字符串
char *gcvt(double value,int ndigit,char *buf)將數(shù)value轉(zhuǎn)換成字符串并存于buf中,并返回buf的指針
char *ultoa(unsigned long value,char *string,int radix)將無(wú)符號(hào)整型數(shù)value轉(zhuǎn)換成字符串并返回該字符串,radix為轉(zhuǎn)換時(shí)所用基數(shù)
char *ltoa(long value,char *string,int radix)將長(zhǎng)整型數(shù)value轉(zhuǎn)換成字符串并返回該字符串,radix為轉(zhuǎn)換時(shí)所用基數(shù)
char *itoa(int value,char *string,int radix)將整數(shù)value轉(zhuǎn)換成字符串存入string,radix為轉(zhuǎn)換時(shí)所用基數(shù)
double atof(char *nptr) 將字符串nptr轉(zhuǎn)換成雙精度數(shù),并返回這個(gè)數(shù),錯(cuò)誤返回0
int atoi(char *nptr) 將字符串nptr轉(zhuǎn)換成整型數(shù), 并返回這個(gè)數(shù),錯(cuò)誤返回0
long atol(char *nptr) 將字符串nptr轉(zhuǎn)換成長(zhǎng)整型數(shù),并返回這個(gè)數(shù),錯(cuò)誤返回0
double strtod(char *str,char **endptr)將字符串str轉(zhuǎn)換成雙精度數(shù),并返回這個(gè)數(shù),
long strtol(char *str,char **endptr,int base)將字符串str轉(zhuǎn)換成長(zhǎng)整型數(shù),并返回這個(gè)數(shù),
int matherr(struct exception *e)用戶修改數(shù)學(xué)錯(cuò)誤返回信息函數(shù)
double _matherr(_mexcep why,char *fun,double *arg1p,
double *arg2p,double retval)用戶修改數(shù)學(xué)錯(cuò)誤返回信息函數(shù)
unsigned int _clear87() 清除浮點(diǎn)狀態(tài)字并返回原來(lái)的浮點(diǎn)狀態(tài)
void _fpreset()重新初使化浮點(diǎn)數(shù)學(xué)程序包
unsigned int _status87() 返回浮點(diǎn)狀態(tài)字