Question

URGENT I NEED HELP! Please and thank you

Answer 1

The expression that correctly determined the value of cos ∠A is

`(8^(2) +10^(2) -(BC)^(2) )/(2*8*10)`

What is the expression ?

Base on Trigonometric law which says the square of one side in a planar triangle is equal to the product of the squares of the other two sides and the cosine of the angle that separates them, less twice the product of those squares.

`cos A =( b^(2)+c^(2) -a^(2) )/(2bc)`

c=8

b=10

Based on the cosine formula the expression that correctly determined the value of cos ∠A is

`(8^(2) +10^(2) -(BC)^(2) )/(2*8*10)`