Given cos A = -.45 find angle A in degrees. Round your answer to the nearest hundredth.

Question

directrix · Answer

@ello_bello  Did you use a calculator to work this problem?

anonymous · Answer

No. These confuse me (Tan, cos, and sin).

anonymous · Answer

I'm doing online school, so I teach my self. The reading is a little confusing.

directrix · Answer

Practice on this problem:  cosA = .5. Give angle A in degrees. See what you get and post here.  Then, we'll do the problem you posted. Okay.

directrix · Answer

Do you have a calculator?

anonymous · Answer

yes I have a TI-83

directrix · Answer

Do you know how to get it to find answers such as cos(A) = .5 ?  I was just using a scientific calculator.

anonymous · Answer

It's soh,cah,toa

directrix · Answer

soh,cah,toa is for finding sides and angles of a right triangle.

If cos A = -.45, then A = 116.74 degrees.

directrix · Answer

I used the online scientific calculator at: http://www.picalc.com/

anonymous · Answer

Thanks I understand now and the online calculator will be handy.

directrix · Answer

cos and acos on that calculator are not the same. 
If you are looking for the angle, use acos.

anonymous · Answer

ok