Posted by **Ria** on Monday, May 17, 2010 at 12:33am.

Let OP be any vector with direction angles theta, beta, and gama.

Explain why cos^2theta + cos^2beta + cos^2gama = 1

- Calculus -
**drwls**, Monday, May 17, 2010 at 6:03am
The Pythagorean therem, applied twice, says that the sum of the squares of projections onto three perpendicular axes, of a segment of any vector with length 1, equals the length of the vector (1)

## Answer this Question

## Related Questions

- Pre Calc. - Use the sum or difference identity to find the exact value of sin255...
- math - How would you establish this identity: (1+sec(beta))/(sec(beta))=(sin^2(...
- Math - sin theta = 8/17 and theta is in the second quadrant. Find sin(2theta),...
- Vector Algebra - Find the direction angles of the vector given below. Then write...
- Calculus - I wanted to confirm that I solved these problems correctly (we had to...
- Precalc+trig - Solve tan(40/90) for the double angle cos(2theta). I know I use ...
- math - There are no typos and no work b/c I don't know how to do them. Thanks. 1...
- algebra - Can someone please help me do this problem? That would be great! ...
- Trigonometry (repost Reiny) - at 1:35am I posted ; Write equivalent equations in...
- trig - given that 1/2pi<theta<pi and sin theta=1/5, use appropriate ...