For what value of y is the expression \(\frac{y + 2}{y^{2} - 3y - 10}\) undefined?
y = 0
y = 2
y = 3
y = 5
y = 10
Correct answer is D
\(\frac{y + 2}{y^2 - 3y - 10}\)
\(y^2 - 3y - 10 = 0 \implies y^2 - 5y + 2y - 10 = 0\)
\(y(y - 5) + 2(y - 5) = 0\)
\((y - 5)(y + 2) = 0\)
\(\frac{y + 2}{(y - 5)(y + 2)} = \frac{1}{y - 5}\)
\(\therefore\) At y = 5, the expression \(\frac{y + 2}{y^2 - 3y - 10}\) is undefined.
Simplify: \((\frac{1}{4})^{-1\frac{1}{2}}\)
1/8
1/4
2
4
8
Correct answer is E
\((\frac{1}{4})^{-1\frac{1}{2}}\)
= \((\frac{1}{4})^{-\frac{3}{2}}\)
= \((\sqrt{\frac{1}{4}})^{-3}\)
= \((\frac{1}{2})^{-3}\)
= \(2^3\)
= 8
Find the number whose logarithm to base 10 is 2.6025
400.4
0.4004
0.04004
0.004004
0.0004004
Correct answer is A
For the log to be 2.6025, there must be three digits before the decimal point.
-4
-1
0
1
4
Correct answer is C
log 6 + log 2 - log 12
= \(\log (\frac{6 \times 2}{12})\)
= \(\log 1\)
= 0
The population of a village is 5846. Express this number to three significant figures
5850
5846
5840
585
584
Correct answer is A
5846 \(\approxeq\) 5850 (to 3 s.f.)