how to solve equation in syms

i know the question is kinda stupid but very much appreciated if somebody could helps

syms x;
cos(10+x-x)

the ans keep showing "cos(10)" but i want it to be solved like -0.839071529076452

Answer 1

[madhan ravi]

syms x pi 
cos(pi+x-x)

[bencsl]

thanks for your answer but my programme doesnot necessary to be 3.14, it was just an example

lets say cos(10+pi-pi)

[madhan ravi]

syms x pi
vpa(cos(10+x-x)) % will match the result in your edited question which was after the answer was given
double(cos(10+pi-pi)) % use double() to convert the result into decimal which of type double because syms result in the class of type sym 

[bencsl]

thx a lot, it cost me 2 hours hahaaa