sec(alpha) = -4(√(5))/5 find exact values at alpha for the remaining five trig functions
1/cosA = =4*sqrt(5)/5
cosA = -5/(4sqrt5) = X/r
X^2 + Y^2 = r^2
(-5)^2 + Y^2 = (4sqrt5)^2
25 + Y^2 = 16*5 = 80
Y^2 = 80-25 = 55
Y = sqrt55.
sin A = Y/r = sqrt55/(4sqrt5).
tan A = Y/X = sqrt55/-5.
cot A = 1/tan A = -5/sqrt55.
csc A = 1/sin A = 4sqrt5/sqrt55.