Vennligst løs q 18?

Vennligst løs q 18?
Anonim

Gitt at # A + B = 90 ^ @ # deretter # A = 90-b ^ @ #

#rarr (tanAtanB + tanAcotB) / (sinAsecB) - (sin ^ 2B) / (cos ^ 2A) #

# = (Tana tanB + cotB) / (sinAsecB) - (sin ^ 2B) / (cos ^ 2 (90 ^ @ - B) #

# = ((Avbryt (sinA) / cosA) sinB / cosBy + cosBy / sinB) / (avbryt (sinA) / cosBy) - (sin ^ 2B) / (sin ^ 2B) #

# = ((1 / cosA) (sin ^ 2B + cos ^ 2B) / (sinB * avbryt (cosBy))) / (1 / avbryt (cosBy)) - 1 #

# = 1 / (cos (90 ^ @ - B) sinB) -1 #

# = 1 / sin ^ 2B-1 = (1-sin ^ 2B) / sin ^ 2B = (cos ^ 2B) / (sin ^ 2B) = cot ^ 2B #

Gitt at # A + B = 90 ^ @ # da er A = 90-B ^ @ #

# (TanAtanB + tanAcotB) / (sinAsecB) - (sin ^ 2B) / (cos ^ 2A) #

# (Tan (90 ^ @ - B) tanB + tan (90 ^ @ - B) cotB) / (sin (90 ^ @ - B) secB) - (sin ^ 2B) / (cos ^ 2 (90 ^ @ - B)) #

# = (CotBtanB + cotBcotB) / (cosBsecB) - (sin ^ 2B) / (sin ^ 2B) #

# = 1 + cot ^ 2B-1 = cot ^ 2B #