Question 1

How do I calculate sin, cos, or tan online?

Accepted Answer

Enter the angle number, then press the sin, cos, or tan button. Make sure the angle mode (DEG or RAD) matches your intended units before pressing the function. In DEG mode: sin(30) = 0.5, cos(60) = 0.5, tan(45) = 1. In RAD mode: sin(π/6) = 0.5. The most common mistake is calculating sin(30) in RAD mode, which gives −0.988, not 0.5.

Question 2

What is the difference between log and ln?

Accepted Answer

log (or log₁₀) is the common logarithm — it answers 'what power of 10 gives this number?' log(100) = 2 because 10² = 100. ln is the natural logarithm — it answers 'what power of e (≈ 2.718) gives this number?' ln(e) = 1, ln(1) = 0, ln(10) ≈ 2.3026. Scientists and engineers use ln for natural growth/decay problems; log is used in pH, decibels, and Richter scale calculations.

Question 3

How do I use DEG vs RAD mode?

Accepted Answer

DEG (degrees) mode: use when angles are in degrees (0° to 360°). Most school-level problems. sin(90°) = 1. RAD (radians) mode: use in calculus, physics, and most higher-level mathematics. A full circle is 2π radians ≈ 6.2832. sin(π/2) = 1. GRAD (gradians) mode: a complete circle is 400 gradians. Mostly used in surveying and some European engineering contexts. Convert: degrees × π/180 = radians. Radians × 180/π = degrees.

Question 4

How do I calculate factorial (n!) on a scientific calculator?

Accepted Answer

Enter the number, then press the n! button. Factorial is only defined for non-negative integers. 5! = 5 × 4 × 3 × 2 × 1 = 120. 10! = 3,628,800. 0! = 1 by convention. Factorials grow very rapidly — 20! is already 2,432,902,008,176,640,000 (about 2.43 × 10¹⁸). Values above about 170! exceed JavaScript's floating-point range and return Infinity.

Question 5

How do I enter scientific notation?

Accepted Answer

Use the EXP button or type 'e' in the keyboard. 3 × 10⁸ is entered as 3 EXP 8 (or 3e8). The calculator also accepts expressions like 1.5e-3 = 0.0015. Results are automatically shown in scientific notation when the value is very large or very small. You can also use the Scientific Notation Converter panel below the calculator to convert between standard and scientific notation with full step-by-step explanation.

Question 6

What are the memory buttons (M+, M−, MR, MC) for?

Accepted Answer

Memory functions let you store and reuse intermediate values: M+ adds the current display value to memory. M− subtracts the current display from memory. MR (Memory Recall) recalls the stored value into the display. MC (Memory Clear) erases the stored memory value. MS (Memory Store) replaces the memory with the current display. Example: Calculate 3 × 7 = 21, press M+. Then calculate 5 × 4 = 20, press M+. Press MR to see 41 — the sum of both results. Memory persists until you press MC or close the page.

Question 7

What is the difference between a scientific and a graphing calculator?

Accepted Answer

A scientific calculator performs advanced mathematical operations — trig, logarithms, powers, roots, factorials, scientific notation, and statistics — but cannot draw graphs. A graphing calculator does everything a scientific calculator does plus visualises functions as graphs on a coordinate plane, allowing you to find intersections, trace functions, and analyse graphs visually. For most school and professional calculation needs, a scientific calculator is sufficient. Only when you need to visualise or explore functions graphically do you need a graphing calculator.

Question 8

How do I calculate powers and roots?

Accepted Answer

Square: Enter a number then press x². Cube: Press x³. Any power: Enter base, press xʸ, enter the exponent, press =. Example: 2 xʸ 10 = 1024. Square root: Press √. Cube root: Press ∛. nth root: Enter n, press ʸ√x, enter the value, press =. Example: 3 ʸ√x 27 = 3 (cube root of 27). Negative exponents: 2 xʸ (−3) = 0.125 = 1/8.

Question 9

What common angle values should I know for trig?

Accepted Answer

Key values in DEG mode — sin(0°)=0, sin(30°)=0.5, sin(45°)=√2/2≈0.7071, sin(60°)=√3/2≈0.8660, sin(90°)=1. cos(0°)=1, cos(30°)=√3/2, cos(45°)=√2/2, cos(60°)=0.5, cos(90°)=0. tan(0°)=0, tan(30°)=1/√3≈0.5774, tan(45°)=1, tan(60°)=√3≈1.7321, tan(90°)=undefined. In RAD mode, replace degrees with radians: 30°=π/6, 45°=π/4, 60°=π/3, 90°=π/2.

Scientific Calculator — sin cos tan, log, ln, DEG RAD & More (Free 2026)

Scientific Calculator Guide — Trig, Logarithms, DEG vs RAD & Keyboard Shortcuts

Trigonometric Functions

Logarithm Rules

Common Trig Values (DEG Mode)

Keyboard Shortcuts

Scientific Calculator — Frequently Asked Questions

Related Calculators

Angle	sin	cos	tan
0°	0	1	0
30°	0.5	0.8660	0.5774
45°	0.7071	0.7071	1
60°	0.8660	0.5	1.7321
90°	1	0	∞
120°	0.8660	−0.5	−1.7321
135°	0.7071	−0.7071	−1
150°	0.5	−0.8660	−0.5774
180°	0	−1	0
270°	−1	0	∞
360°	0	1	0