Solving Log Equations Flashcards
Product Law
Logb = log[b]m + log[b]n
When adding logs of same base multiply, or when multiplying add.
Quotient Law
logb = log[b]m - log[b]n
When subtracting logs of same base divide, when dividing subtract
Simplify? Evaluate? Evaluate exactly?
Simplify: write in simplest form. Ex. log14. Evaluate: solve even to fractions or decimals. Evaluate exactly: only whole numbers or fractions
Techniques for solving exp equation
If the equation can be written w/a common base do it! If it cant easily, use logs. If more complicated, creatively choose an effective mathematical solution
Prove Quotient Law
Let log[b]m = x and log[b]n = y
m / n = b^x / b^y
m / n = b^(x-y)
How to solve exponential equations with completely different bases?
write as base of one number. Ex. 3^x = 2^x+2 can be (2^log3/log2)^x = 2^x+2. OR take log of both sides.