Answer
a) not possible
b) possible
c) possible
Work Step by Step
a) For any angle $\theta$, secant cannot be in following interval $-1\lt\sec\theta\lt1$, therefore $\sec\theta=\frac{-2}{3}$ is impossible
b) Tangent can be any real number, therefore $\tan\theta=1.4$ is possible.
c) For any angle $\theta$, cosecant cannot be in following interval $-1\lt\csc\theta\lt1$, therefore $\csc\theta=5$ is possible.
