(a) Estimate the value of lim X 4x+ 3+x) X- -Co by graphing the function f(x) = \\x2 4 x + 3 + x. (Round your answer to one decimal place.) (b) Use a table of values of f(x) to guess the value of the limit. ( Round your answer to one decimal place (c) Prove that your guess is correct by evaluating lim f(x)