Given:
A triangle ABC.
The given expression for b is:
To find:
The expression that is equivalent to b.
Solution:
According to the Law of Cosines,
It can be written as:
...(i)
We have,
...(ii)
On comparing (i) and (ii), we get
Therefore, the required values are .
Answer:
The true statements are;
(i) m - n = n - m
(ii) +m (-n) = m - n
(iii) 0 = m - n
Step-by-step explanation:
We are given that m and n are both integers and we have to select all the statements that are true if m and n are also equal to each other.
(i) The given situation is: m - n = n - m
LHS = m - n
= m - m {because m and n are equal}
= 0
RHS = n - m
= n - n {because m and n are equal}
= 0
Hence, the given statement is true because LHS = RHS = 0.
(ii) The given situation is: +m (- n) = m - n
LHS = +m (- n)
= m - n
= m - m {because m and n are equal}
= 0
RHS = m - n
= n - n {because m and n are equal}
= 0
Hence, the given statement is true because LHS = RHS = 0.
(iii) The given situation is: 0 = m - n
LHS = 0
RHS = m - n
= m - m {because m and n are equal}
= 0
Hence, the given statement is true because LHS = RHS = 0.
(iv) The given situation is: m + n = 0
RHS = 0
LHS = m + n
= m + m {because m and n are equal}
= 2m
Hence, the given statement is not true because LHS RHS.