How do you plug the inverse csc (-7/3) into the calculator?

2 Answers
Jul 28, 2015

Use the inverse sine function.

Explanation:

#csc^-1(-7/3)# is a number between #-pi/2# and #pi/2# whose cosecant is #-7/3#).

That means the sine is #-3/7#.

#csc^-1(-7/3) = sin^-1(-3/7)#.

In general,
because #csc theta = 1/sin theta#,

we have: #csc^-1 x = sin^-1 (1/x)#

Note: we use a similar idea to find inverse secant and inverse cotangent on many calculators.

#sec^-1 x = cos^-1(1/x)#

and

#cot^-1 x = tan^-1(1/x)#

(The last works if we take the range of #cot^-1# to be the same as that of #tan^-1# -- a popular choice in this computer age.
The description is a bit more complicated if we take the range of #cot^-1 x# to be the same as that of #cos^-1# -- a traditional choice that makes the inverse cotangent continuous.)

Jul 28, 2015

Plug in calculator to find csc(-7/3)

Ans: arc x = -25.37 deg

Explanation:

Order of plug in:

(7) (:) (3) (=) (-) (1/x) (2nd) (sin)

The answer will be #x = - 25.37# deg