Solution

prove

Solution

Solution steps
Use the Angle Sum identity:

Popular Examples

prove (1+tan(θ))^2=sec^2(θ)+2tan(θ)prove (1-tan(θ))^2=sec^2(θ)-2tan(θ)prove 4sin(x/4)cos(x/4)cos(x/2)=sin(x)prove (sin(θ)+sin(3θ))/(2sin(2θ))=cos(θ)prove cos(2A)=1-2sin^2(A)

Frequently Asked Questions (FAQ)

  • Is cos(a+b)=cos(a)cos(b)-sin(a)sin(b) ?

    The answer to whether cos(a+b)=cos(a)cos(b)-sin(a)sin(b) is True