Final answer:
The numerical value of cscθ when θ = 90 degrees is 1, since the sine of 90 degrees is 1 and the cosecant function is the reciprocal of the sine function.
Step-by-step explanation:
To determine the numerical value of the cosecant function when θ = 90 degrees, we first need to recall the definition of the cosecant (csc) function. The cosecant of an angle is the reciprocal of the sine of that angle. Therefore, cscθ = 1/sinθ. Knowing that sin(90 degrees) = 1, the numerical value of csc(90 degrees) is simply 1/sin(90 degrees) which equals 1/1, resulting in csc(90 degrees) = 1.