if tanA=1 and tanB=root 3 .find cosA×cosB-sinA×sinB
Answers
Answered by
2
tan A =1 and tan 45°=1
=>A=45°
tan B = √3 and tan60°=√3
=>B=60°
.: cos A.cosB-sinA.sinB
=cos 45° * cos60° - sin45° *sin60°
=1/√2(1/2-√3/2)
=1/√2 * (1-√3)/2
=(1-√3)/2√2
=>A=45°
tan B = √3 and tan60°=√3
=>B=60°
.: cos A.cosB-sinA.sinB
=cos 45° * cos60° - sin45° *sin60°
=1/√2(1/2-√3/2)
=1/√2 * (1-√3)/2
=(1-√3)/2√2
Similar questions