Question

a=b+c-2bc x cos A ? Simplify.. trig?

Answer 1

solve for A?

Answer 2

Yes

Answer 3

that is a^2=b^2+c^2-2bc c0s A

Answer 4

Explain pleasee

Answer 5

law of cosines right?

Answer 6

and it cannot mean "simplify" maybe it means "solve for \(A\)"

Answer 7

\[a^2=b^2+c^2-2bc\cos(A)\]
\[a^2-b^2-c^2=-2bc\cos(A)\]
\[\frac{b^2+c^2-a^2}{2bc}=\cos(A)\]
\[A=\cos^{-1}\left(\frac{b^2+c^2-a^2}{2bc}\right)\]

Answer 8

OMG thanks so much!!

Answer 9

yw