NOTE:- Preferable to use yacc/bison and give Seperate code for yacc and bison.. Also write a brief note on working of code.

Question Use lex/flex and yacc/bison to create a scientific calculator. Include power, cos, sin, tan, log and sqrt functions, in addition to the basic arithmetic operators, to the functionality of your calculator. Extend this calculator to handle variables with single letter names to use floating point values. Ensure the precedence and associativity of the operators. Give the source code and the runtime screen with compilation and execution steps. Test script is given below. a = 10.00 b = 20.0897 c = sin(a)+cos(root(b))