Advertisements
Advertisements
Question
Express A in terms of others:
2 log A – log S = log (S – a) + log (S – b) + log (S – c)
Sum
Advertisements
Solution
We are given:
2 log A – log S = log (S – a) + log (S – b) + log (S – c)
Step 1: Combine both sides
Left side:
`2 log A - log S = log A^2 - log S = log (A^2/S)`
Right side:
log (S – a) + log (S – b) + log (S – c) = log [(S – a)(S – b)(S – c)]
Now the equation becomes:
`log(A^2/S) = log[(S - a)(S - b)(S - c)]`
Step 2: Equate the arguments
`A^2/S = (S - a)(S - b)(S - c)`
Multiply both sides by S:
`A^2 = S(S - a)(S - b)(S - c)`
⇒ `A = sqrt(S(S - a)(S - b)(S - c))`
shaalaa.com
Is there an error in this question or solution?
Chapter 7: Logarithms - EXERCISE 7B [Page 75]
