Bentuk sederhana 2cos(A+π/4).cos(3/4-A)+1
Jawaban Terkonfirmasi
Jawab
2 cos (A + π/4) cos (3/4 π – A) + 1 =
= cos (A + π/4 + 3/4 π – A) cos (A + π/4 – 3/4 π + A) + 1
= cos (π) cos (2A – 1/2 π) + 1
= (-1) cos (1/2 π – 2A) + 1
= - sin (2A) + 1
= 1 – sin 2A
= 1 – 2 sin A cos A