Bagaimana anda mempermudahkan f (theta) = sin4theta-cos6theta kepada fungsi trigonometri daripada theta unit?

Bagaimana anda mempermudahkan f (theta) = sin4theta-cos6theta kepada fungsi trigonometri daripada theta unit?
Anonim

Jawapan:

4sos (theta) ^ 4-4cos (theta) sin (theta) ^ 3 + 15cos (theta) ^ 4sin (theta) ^ 2 + 4cos (theta) ^ 3sin (theta) -cos (theta) ^ 6 #

Penjelasan:

Kami akan menggunakan dua identiti berikut:

#sin (A + -B) = sinAcosB + -cosAsinB #

#cos (A + -B) = cosAcosB sinAsinB #

cos (2ta) (2ta) = 2 (2sin (theta) cos (theta)) (cos ^ 2 (theta) -sin ^ 2 (theta)) = 4sin (theta) cos ^ theta) -4sin ^ 3 (theta) cos (theta) #

#cos (6theta) = cos ^ 2 (3theta) -sin ^ 2 (3theta) #

(2ta) sin (theta)) ^ 2 (sin (2theta) cos (theta) + cos (2theta) sin (theta)) ^ 2 #

(= theta) -sin ^ 2 (theta)) - 2sin ^ 2 (theta) cos (theta)) ^ 2- (2cos ^ 2 (theta) sin (theta) (theta) (cos ^ 2 (theta) -in ^ 2 (theta)) ^ 2 #

cos = theta) -2in ^ 2 (theta) cos (theta) -2in ^ 2 (theta) cos (theta)) ^ 2- (2cos ^ 2 (theta) sin (theta) (theta) sin (theta) -in ^ 3 (theta)) ^ 2 #

# = (cos ^ 3 (theta) -3sin ^ 2 (theta) cos (theta)) ^ 2- (3cos ^ 2 (theta) sin (theta)

cos == cos ^ 6 (theta) -6sin ^ 2 (theta) cos ^ 4 (theta) + 9sin ^ 4 (theta) cos ^ 2 (theta) -9sin ^ 2 (theta) cos ^ 4 (theta) + 6sin ^ 4 (theta) cos ^ 2 (theta) -sin ^ 6 (theta) #

cos (6ta) - 4sin (theta) cos ^ 3 (theta) -4sin ^ 3 (theta) cos (theta) - (cos ^ 6 (theta) -6sin ^ 2 (theta) cos ^ (theta) + 9sin ^ 4 (theta) cos ^ 2 (theta) -9sin ^ 2 (theta) cos ^ 4 (theta) + 6sin ^ 4 (theta) cos ^ 2 (theta) #

Cos = 3 (theta) -4sin ^ 3 (theta) cos (theta) -cos ^ 6 (theta) + 6sin ^ 2 (theta) cos ^ 4 (theta) -9sin ^ 4 (theta) cos ^ 2 (theta) + 9sin ^ 2 (theta) cos ^ 4 (theta) -6sin ^ 4 (theta) cos ^ 2 (theta) + sin ^ 6 (theta)

# = sin (theta) ^ 6-15cos (theta) ^ 2sin (theta) ^ 4-4cos (theta) sin (theta) ^ 3 + 15cos (theta) ^ 4sin (theta) ^ 2 + 4cos (theta) ^ 3sin (theta) -cos (theta) ^ 6 #