Calculate sin(θ/2), cos(θ/2), or tan(θ/2) using half angle formulas.
Enter your values below
How this calculator works
Half angle formulas express trig functions of θ/2 in terms of functions of θ: sin(θ/2)=±√((1−cosθ)/2), cos(θ/2)=±√((1+cosθ)/2), tan(θ/2)=sinθ/(1+cosθ).
Common questions about this calculator
