Question

Find the error in the solution. Identify the solution, and then solve the problem correctly.

In ΔKLM, m Use the Law of Cosines to find the length of LM to the nearest tenth.
LM² = 23² - 20² - 2 (23) (20) cos 119°
LM² = 529 - 400 - 920 cos 119°
LM²≈575.02
LM²≈24.0

Answer 1

Eroor: LM² = 23² - 20² - 2(23)(20) cos 119°

Should be LM² = 23² + 20² - 2(23)(20) cos 119°

Lm² = 575.02 is incorrect

LM² = 1375.016 is correct

LM = 24.0 is incorrect

LM = 37 - 1 is correct

Answer: LM = 37 - 1

Explanation:

`In\ \bigtriangleup KLM`

`By\ using\ cosine\ gule:`

`LM^2=LK^2+Km^2-2LK* Km`

`* cos(119\textdegree`

`LM^2=23^2+20^2-2* 23* 20* -0.4848`

`LM^2=529+400+920* 0.4848`

`LM^2=929+446+016=1375.016`

`LM=√(1375.016)=37.0812=37.1`

`Error:LM^2=23^2-20^2-2(23)(20)cos\ 119\textdegree`

`Sholeld\ be\ 2M^2=23^2+20^2-2(23)(20)\ cos\ 119\textdegree`

`Lm^2=575.02\ is\ incosrect`

`LM^2=1375.016\ is\ correct`

`LM=24.0\ is\ correct`

`Lm=37-1\ is\ correct`

`Answer:LM=37-1`

I hope this helps you

:)