practice exam help? (1 Viewer)

[hscishard]

AM I CRAZY???????

this question does not work!

Q3ai

Triangle ABC has sides AB=3cm, BC=6cm and CA=5cm.

Use the cosine rule to show that Angle BAC = 94 degrees.

I keep getting a negative answer - HELP!

the cosine rule is getting me a negative answer!!!

and i need "sinC" before i can do area of triangle!!!

I hate people that can only use calculators, AND can't use them properly.

(9+25 -36)/ (2x5x3)
=-1/15
Shift cos, angle is approx 93.82