Errata

Frequently Updated

The Essential Guide to Algebra 1 (개정판)

Last update : 2023.05.22
# Page Number Question Number Errata
1 p.97 4 Change from $100$ to $101$.
2 p.207 7(a) Change from $\frac{1}{2}$ to $\frac{x}{2}$.
3 p.236 5(c) Change from $-\frac{4}{9}$ to $-\frac{4}{5}$.
4 p.243 2 Turn the last phrase into `from least to greatest`.

The Essential Guide to Geometry (초판)

Last update : 2021.08.10
# Page Number Question Number Errata
1 p.170 88 Change from $20$ to $30$.
2 p.170 89 Change from $\sqrt{2}$ into $\frac{1}{\sqrt{2}}$.

The Essential Guide to Algebra 2 (개정판)

Last update : 2022.06.25
# Page Number Question Number Errata
1 p.30 7 Change from $-8$ to $2$.
2 p.30 8 Change from $7$ to $8$.
3 p.140 16(c) Change from $-x^2$ to $x^2$.
4 p.141 17(b) Change from $x^2+x^2$ to $x^3+x^2$.
5 p.173 6 Change from $4$ to $-4$.
6 p.302 # Change from invNorm$(0.89,9,1)$ to invNorm$(0.89,0,1)$.

The Essential Guide to Precalculus (초판)

Last update : 2022.06.23
# Page Number Question Number Errata
1 p.43 3 Put `real number` in front of $x$.
2 p.47 17 Turn `tangent` to `tangent to`.
3 p.56 14 Get rid of the last expression.
4 p.64 24 Turn `Find the value of $p$` into `Find the minimum value`.
5 p.87 1 Change from $4$ into $-4$.
6 p.105 1 $\begin{align*} &\log(6)+\log(2)\\ &=\log(6)+(1-\log(5))\\ &=a+1-b \end{align*}$
7 p.105 4 Turn $z=\log_x(\log_y(x))$ into $x^z=\log_y(x)$.
8 p.157 N/A The correct statement is `Both sine and tangent are odd functions, whereas cosine is even`.
9 p.160 5 Turn $\cos(42)$ into $\cos(48)$.
10 p.237 1 Turn $-\frac{2\pi}{3}$ into $\frac{2\pi}{3}$.
11 p.274 4 Turn `$n=\frac{e}{2}$, $mn=\frac{e}{4}$` into `$n=2e$, $mn=e$`.
12 p.275 11 Turn `$x=2$` into `$x=16$`.
13 p.285 5 Turn $\cos(42)$ into $\cos(48)$.
14 p.286 10 Turn `$\sin(6x)=\sin(x)$` into $\sin(6x)+\sin(4x)$`.
15 p.288 5 Turn `$\sqrt{42}-\sqrt{2}$` into `$\sqrt{42}\pm\sqrt{2}$`.
16 p.290 14 Get rid of $\sqrt{5}$ in the numerators.
17 p.294 3(a) Turn `$(2,\frac{5\pi}{6})$` into `$(2,\frac{11\pi}{6})$`.