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