Please help me EVALUATE : csc[Sin^-1(-2/3) + Tan^-1(3/4) - Cos^-1(-4/5)]

Sin^-1(-2/3) = A
sinA = -2/3
cscA = -3/2
A = csc^-1(-3/2)

Tan^-1(3/4) = B
tanB = 3/4
tan²B = 9/16
sec²B - 1 = 9/16
sec²B = 25/16
secB = 5/4
cosB = 4/5
B= cos^-1(4/5)

Cos^-1(-4/5) = C
cosC = -4/5
-cosC = 4/5
cos(π - C) = 4/5
π - C = cos^-1(4/5)
C = π - cos^-1(4/5)


csc[A + B + C]= csc[A + cos^-1(4/5) + π - cos^-1(4/5)]
csc[A+B+C] = csc[π + A]
= -cscA
= -csc[csc^-1(-3/2)]
= -3/2