Question

cot(cos^-1u)
please help!!

Answer 1

cot(cos^-1 (w)) = cos(cos^-1(w)) / sin(cos^-1(w))

The numerator simplifies to w.

Remember that sin^2 x + cos^2 x = 1
So the denominator is either √(1-w^2) or -√(1-w^2)
Remember also that the range of cos^-1 is 0 to pi, which is in the first two quadrants, so sin is always positive there.
That makes the denominator √(1-w^2)

So we end up with:
w / √(1-w^2)

If you want to rationalize the denominator, multiply the whole thing by √(1-w^2) and end up with:
w√(1-w^2) / (1-w^2)

Answer 2

Have you considered a Right Triangle?

The Cosine of some anngle is "u". What is the cotanget of the same angle?

You will need the triangle definition of Cosine.
You will need the Pythagorean Theorem
You will need the triangle definition of Cotangent.

Answer 3

@JESS84 Please do not simply repost the same question. If you do not understand say so. If you did already say so, please show SOME effort and understanding. If you TRULY have no idea, you are in the wrong class. Something seriously wrong with that.

From the previous responses you have received, there has been quite a lot of algebra. There really doesn't need to be that much.

Draw a Right Triangle and designate one of the Acute angles. Call it whatever you like. You will begin to see it. DRAW the Right Triangle!

Answer 4

Was not really sure how this worked so my apology. If I understood the question I would not have asked it. Thank you for the help. I truly appreciate it. I am taking an online class and its not always easy to understand.

Answer 5

The more I see online math classes, the less I am impressed. I think we're just not very good at it, yet.

Anyway, did you get this one?