Qual é o cosseno de menos 2π/9 radiano(s)? cos(-2π/9^rad)?

Calculator use

To use this calculator, just type a value for the angle, then press 'Calculate'. You may choose radians (rad) or degrees (°) as the angle unit. The default unit is degree (°)

Examples of accepted input values

• 30 → sin(30°) = 0.5
• pi → sin(pi^rad) = 0
• 3pi/4 → sin(3pi/4) = 0.707 ...
• 1/(2pi) → sin(1/(2pi)^rad) = 0.158 ... (note the parenthesis in denominator)
• 1/2pi → sin(1/2pi^rad) = sin((1/2) x pi^rad) = 1 exactly

Note: this calculator accepts numbers, fractions, 'pi', 'π', '+', '-', '*', '/', '(', ')' and some (not all) combinations of them as input. Use it with care!