A scientific calculator can combine trigonometry, logarithms, powers, and factorials, but the right formula can still yield the wrong answer if the mode is wrong.
Check whether angles are in degrees or radians before using sine and cosine. Verify parentheses and order of operations with a simple reference calculation. For logarithms, know whether the function is base 10 or natural log. Values outside a function's domain should be reported as errors rather than silently transformed.
Floating-point results may be rounded, so do not confuse a long decimal display with exact precision. For important calculations, write down the expression, units, and calculator settings and cross-check independently.
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