Question #47acb

1 Answer
Mar 16, 2017

Let's write sec(theta) = -4.5 as sec(theta) = -9/2

Then:

cos(theta) = 1/sec(theta)

cos(theta) = -2/9

And:

sin^2(theta) = 1- (-2/9)^2" [1]"

When we take square root of both sides of equation [1], we must use +- on the right:

sin(theta) = +-sqrt(1-(2/9)^2)

We are given that theta is the second quadrant and we know that the sine function is positive in the second quadrant so we drop the +-, thereby, indicating only the positive value:

sin(theta) = sqrt(1-(2/9)^2)

sin(theta) = sqrt(81/81-4/81)

sin(theta) = sqrt(77/81)

sin(theta) = sqrt(77)/9

tan(theta) = sin(theta)/cos(theta)

tan(theta) = (sqrt(77)/9)/(-2/9)

tan(theta) = -sqrt(77)/2

cot(theta) = 1/tan(theta)

cot(theta) = -2/sqrt(77) = -2sqrt77/77

csc(theta) = 1/sin(theta)

csc(theta) = 9/sqrt77

csc(theta) = 9sqrt77/77