Question

A=2 b=2 c=1 Find the value of 2abcosC

Answer 1

Answer:

$2abCosC = 1$

Step-by-step explanation:

The cosine rule is

=> $a^2= b^2+c^2-2abCosC$

For 2abCosC, it becomes

=> $2abCosC = b^2+c^2-a^2$

=> $2abCosC = (2)^2+(1)^2-(2)^2$

=> $2abCosC = 1$