Bevis at ((cos (33 ^ @)) ^ 2- (cos (57 ^ @)) 2) / ((sin (10,5 ^ @)) ^ 2- (sin (34,5 ^ @)) 2) = -sqrt2?

Bevis at ((cos (33 ^ @)) ^ 2- (cos (57 ^ @)) 2) / ((sin (10,5 ^ @)) ^ 2- (sin (34,5 ^ @)) 2) = -sqrt2?
Anonim

Svar:

Se nedenfor.

Forklaring:

Vi bruker formler (A) - # CosA = sin (90 ^ @ - A) #, (B) - # cos ^ 2A-sin ^ 2A = cos2A #

(C) - # 2sinAcosA = sin2A #, (D) - # SinA + sinB = 2sin ((A + B) / 2) cos ((A-B) / 2) # og

(E) - # SinA-sinB = 2cos ((A + B) / 2) sin ((A-B) / 2) #

# (cos ^ 2 33 ^ @ cos ^ 2 57 ^ @) / (sin ^ 2 10,52 @ -sin2 34,5 ^ @) #

= # (cos ^ 2 33 ^ @ sin ^ 2 (90 ^ @ 57 ^ @)) ((sin10.5 ^ + sin34.5 ^) (sin10.5 ^ @ sin34.5 ^)) # - brukt EN

= # (cos ^ 2 33 ^ @ - sin ^ 2 33 ^ @) / (- (2sin22.5^ @ cos12 ^ @) (2cos22.52@sin12 ^ @)) # - brukt D & E

= # (Cos66 ^ @) / (- (2sin22.5 ^ @ ^ @ cos22.5 xx2sin12 ^ @ ^ @ cos12) # - brukt B

= # - (sin (90 ^ @ - 66 ^ @)) / (sin45 ^ @ ^ @ sin24) # - brukt A & C

= # -Sin24 ^ @ / (1 / sqrt2sin24 ^ @) #

= # -Sqrt2 #