% man cos[Enter]

acos	inverse trigonometric function
acosf	inverse trigonometric function
acosh	inverse hyperbolic function
asin	inverse trigonometric function
asinf	inverse trigonometric function
asinh	inverse hyperbolic function
atan	inverse trigonometric function
atanf	inverse trigonometric function
atanh	inverse hyperbolic function
atan2	inverse trigonometric function
atan2f	inverse trigonometric function
cabs	complex absolute value
cabsf	complex absolute value
cbrt	cube root
ceil	integer no less than
ceilf	integer no less than
copysign	copy sign bit
cos	trigonometric function
cosf	trigonometric function
cosh	hyperbolic function
coshf	hyperbolic function
drem	remainder
erf	error function
erfc	complementary error function
exp	exponential
expf	exponential
expm1	exp(x)-1
expm1f	exp(x)-1
fabs	absolute value
fabsf	absolute value
finite	floating point arithmetic
floor	integer no greater than
floorf	integer no greater than
fmod	remainder function
fmodf	remainder function
hypot	Euclidean distance
hypotf	Euclidean distance
j0	bessel function
j1	bessel function
jn	bessel function
lgamma	log gamma function
log	natural logarithm
logf	natural logarithm
logb	exponent extraction
log10	logarithm to base
log10f	logarithm to base
log1p	log(1+x)
log1pf	log(1+x)
pow	exponential x**y
powf	exponential x**y
rint	round to nearest integer
sin	trigonometric function
sinf	trigonometric function
sinh	hyperbolic function
sinhf	hyperbolic function
sqrt	square root
sqrtf	square root
tan	trigonometric function
tanf	trigonometric function
tanh	hyperbolic function
tanhf	hyperbolic function
trunc	truncate to whole number
truncf	truncate to whole number
y0	bessel function
y1	bessel function
yn	bessel function