When compile finished example compiler give me this error:

mimmo@LeoNida:~/SSL_Tutorial/finished_src/echoclient$ make
gcc -o echoclient ../lib/*.c tcpcli01.c -I ../include -I /usr/local/cyassl/include -L/usr/local/cyassl/lib -lcyassl
../lib/error.c: In function ‘err_doit’:
../lib/error.c:102: warning: format not a string literal and no format arguments
tcpcli01.c: In function ‘str_cli’:
tcpcli01.c:19: warning: comparison between pointer and integer
/usr/local/cyassl/lib/libcyassl.so: undefined reference to `log'
/usr/local/cyassl/lib/libcyassl.so: undefined reference to `pow'
collect2: ld returned 1 exit status
make: *** [echoclient] Errore 1

to resolve add into Makefile before -lcyassl, -lm