Scientific calculator: functions and angle modes
A scientific calculator extends basic arithmetic with powers, roots, logarithms, and trigonometric functions. It is useful to evaluate an expression and to verify intermediate values, but the result still depends on the exact expression and settings you enter.
Order of operations
Use parentheses to make the intended order explicit. For example, 2 + 3 × 4 evaluates to 14 because multiplication is performed before addition; (2 + 3) × 4 evaluates to 20. For powers and roots, check exactly which value is inside the exponent or radical.
Degrees and radians
Trigonometric functions such as sine, cosine, and tangent use an angle unit. In degree mode, sin(30°) = 0.5; in radian mode the input must be written in radians, and 30 radians is not the same as 30 degrees. Confirm the current angle mode before comparing your result with a textbook or class assignment.
Domain and rounding
Some expressions are undefined over the real numbers—for example, division by zero or the real logarithm of a nonpositive value. Decimal displays are also rounded, so a displayed approximation may not be exact. When precision is important, keep extra digits in intermediate steps and check the final answer independently.
Tips for accurate results
Use parentheses to control the order of operations, which follows exponents first, then multiplication and division, then addition and subtraction. Choose degrees or radians before using trigonometric functions, and use the memory or previous-answer features for multi-step problems.
Common mistakes and limits
The most common mistakes are the wrong angle mode, missing parentheses around numerators and denominators, and mistyping negative signs. Floating-point arithmetic can leave tiny errors, so a result like 0.30000000000000004 for 0.1 + 0.2 is a display artifact, not a mistake in your math.