Typing the cosine rule into my calculator?

I'm doing the cosine rule on my scientific calculator - the cosine rule to find the angle which is the rule cos A= B SQUARED + C squared- A squared divided by 2x a x b - I know I have to put equal signs and brackets in certain places but I can't remember where. The question i'm trying to do is cos A=1.7 squared + 3.8 squared - 2.9 squared divided by 2 x 1.7 x 3.8. Thankyou :)