about undefined reference for 'sinf'

[bharat suthar]

I m writting code in c using another library(parapin) and making Makefile .but there is a error like
undefined reference to `sinf'
undefined reference to `ceilf'
although i have added math.h library in my code
. I tried to run simple programme using math.h
and it run.but in making Makefile it is giving me error

[kermit]

Are you linking the math library?

all: foo

CC = gcc

CFLAGS = -Wall

foo: foo.o
	$(CC) -o foo foo.o -lm
foo.o: foo.c
	$(CC) $(CFLAGS) -c foo.c