# Homework Help: I insert in my calculator cos 50x60 = 42.42

1. Dec 11, 2011

### luigihs

1) cos 60o = vx0 / 50 => vx0 = 50.cos 60o = ?
2) sin 60o = vy0 / 50 => vy0 = 50.sin 60o = ?

OK so I use my calculator for 1) and I insert in my calculator cos 50x60 = 42.42 but this is not the right answer because the answer is 25 m/s because the answers are in the back of my book.

FOr question number 2) I not 100 % sure but I do the same thing sin 50x60 = 42.42 in this case I get the same answer than in cos, and the answer is 43 m/s so I dont know about this because I got 42.42 so maybe this is right.

Last edited: Dec 11, 2011
2. Dec 11, 2011

### Staff: Mentor

Re: Trigonometry

What does your calculator give you for cos(60°) ?

3. Dec 11, 2011

### luigihs

Re: Trigonometry

0.5877 ... but then I restart my calculator and I get 0.5

4. Dec 11, 2011

### Staff: Mentor

Re: Trigonometry

Your calculator was set to treat angles in 'grads' rather than degrees. There are 400 grads in a circle of 360 degrees.

5. Dec 11, 2011

### luigihs

Re: Trigonometry

But now that I restarted I get in cos 38.567 but I don't get 25 m/s .... and in sin I get now 45.96 and I suppose to get 43 m/s :(

6. Dec 11, 2011

### Staff: Mentor

Re: Trigonometry

More finger problems

You've taken the cosine of 50 degrees and multiplied by 60 rather than take the cosine of 60 degrees and multiply by 50.

7. Dec 11, 2011

### luigihs

Re: Trigonometry

YEAHHH!!! Thanks!!! :)