Check the problem.

If sinx - cosx = 0 then x = 45 degrees.

Now

arcsinx+arccosx = π/2

arcsinx-arccosx = arcsinx+arccosx - 2arcosx = 0

π/2 -2arccosx = 0

Solve for x.

Results 1 to 3 of 3

- Sep 18th 2010, 05:03 AM #1

- Joined
- Sep 2009
- Posts
- 106

- Sep 18th 2010, 05:20 AM #2

- Joined
- Jun 2009
- Posts
- 806
- Thanks
- 4

- Sep 18th 2010, 06:34 AM #3

- Joined
- May 2006
- From
- Lexington, MA (USA)
- Posts
- 12,028
- Thanks
- 846

Hello, aeroflix!

Solve: .

i know x is 45 . . This is wrong!

.[1]

.[2]

The equation becomes: .

Take the sine of both sides: .

and we have: .

Substitute [1] and [2]: .

. .

Therefore: .

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

I tried tomy answers and ran into a new puzzle.*check*

. . (New to*me*, anyway.)

First, I assumed that the angles are in

Then I tested

We have: . .Does it equal 0 ?

We know that: .

So we have: .

The equation is true**if**we select from both sets.

Query: .*Are we allowed to do that?*