1. Show that:
logyx+logzy+logxz=0
2. Show that:
log6241+log12241+log8241=2
3. If x=logcab, y=logabc, z=logbca, prove that:
1+x1+1+y1+1+z1=1
4. Prove that:
2log76+21log1681+log27196=log12
Answer: All four logarithmic statements are proven:
1. log(yx)+log(zy)+log(xz)=0
2. log6241+log12241+log8241=2
3. 1+x1+1+y1+1+z1=1
4. 2log(76)+21log(1681)+log(27196)=log12
Step-by-step solution
Step 1: Solve Question 1 using Logarithmic Product Rule
We use the product property of logarithms, log(a)+log(b)+log(c)=log(abc). Multiplying the three arguments gives yx×zy×xz=1. Since log(1)=0, the sum evaluates directly to 0.
Step 2: Solve Question 2 using Base-Change Property
Applying the reciprocal base property logba1=logab, the expression becomes log246+log2412+log248. Now all logarithms share the common base 24, so we combine them by multiplying their arguments.
Step 3: Evaluate the Product for Question 2
Multiplying the arguments gives 6×12×8=576. Since 576=242, we simplify log24(242) to 2×1=2, proving the given statement.
Step 4: Solve Question 3: Simplify Denominators
We rewrite 1 as logcc. Adding x=logc(ab) yields 1+x=logc(abc). Taking the reciprocal gives 1+x1=logabcc. By identical symmetry, 1+y1=logabca and 1+z1=logabcb.
Step 5: Sum the Symmetrical Terms for Question 3
We add the three simplified fractions together: logabcc+logabca+logabcb. Using the product rule, this equals logabc(abc), which equals 1.
Step 6: Solve Question 4: Apply Power Rule and Combine
Using the power rule klog(u)=log(uk), we rewrite the terms as log(4936), log(49), and log(27196). Then, we combine them into a single logarithm using the product rule.
Step 7: Simplify Fractions for Question 4
Cancelling common factors: 49196=4, 436=9, and 279×4=2736=34. Multiplying 9×31×4=12. Therefore, the expression simplifies to log12.