Calculating lim f (x) 20 - a A. Direct substitution Try to evaluate the function directly. f (a ) f (a) = " f(a) =b f(a) = where b is not zero where b is a real number B. Asymptote C. Limit found D. Indeterminate form (probably) (probably) Try rewriting the limit in an equivalent form. E. Factoring F. Conjugates G. Trig identities Try evaluating the limit in its new form. H. Approximation When all else fails, graphs and tables can help approximate limits. A. Direct substitution B. Asymptote C. Limit found D. Indeterminate form E. Factoring F. Conjugates G. Trig identities H. Approximation