App description

Trigonometric function and differential product formula

\(cosα+cosβ=2cos[(α+β)/2]·cos[(α-β)/2]\)

\(sinα+sinβ=2sin[(α+β)/2]·cos[(α-β)/2]\)

\(cosα-cosβ=-2sin[(α+β)/2]·sin[(α-β)/2]\)

\(sinα-sinβ=2cos[(α+β)/2]·sin[(α-β)/2]\)