Question

Find the value of b.

Answer 1

9.8

17.9

4.1

96.2

Answer 2

Law of Cosines

Answer 3

I'm completely lost

Answer 4

Have you heard of the law of cosines? It's what you need to use to find \(b\).

Answer 5

a2 = b2 + c2 – 2bc cos A ?

Answer 6

like idk how to put it into an equation. very confusing

Answer 7

Yes. You need to use the form of the law of cosines that will give you \(b\).

Answer 8

Look at what you have: \(a\), \(c\), and \(B\).
You are looking for \(b\).

Answer 9

so a2 = b2 + 15^2 -0.91

Answer 10

You have \(\rm \color{red}{these}.\)
You are looking for \(\rm\color{blue}{this}.\)

\(\color{blue}{b}^2 = \color{red}{a}^2 + \color{red}{c}^2 -2\color{red}{ac} \cos \color{red}{B}\)

Answer 11

idk lol

Answer 12

ohh

Answer 13

\(\color{blue}{b}^2 = \color{red}{9}^2 + \color{red}{15}^2 -2 \cdot\color{red}{9 \cdot 15} \cdot \cos \color{red}{39^o}\)

Answer 14

Calculate the right side to find \(b^2\), then take the square root to find \(b\).

Answer 15

so its 9 ?

Answer 16

Did you get just 9, or 9 point something?