diff --git a/source/linear-algebra/source/01-LE/02.ptx b/source/linear-algebra/source/01-LE/02.ptx
index 2d16ffb70..4191459c3 100644
--- a/source/linear-algebra/source/01-LE/02.ptx
+++ b/source/linear-algebra/source/01-LE/02.ptx
@@ -859,9 +859,9 @@ rref(A)
-
+
-
+
format rat
diff --git a/source/linear-algebra/source/01-LE/03.ptx b/source/linear-algebra/source/01-LE/03.ptx
index 5899d5d9f..aa7c58bc3 100644
--- a/source/linear-algebra/source/01-LE/03.ptx
+++ b/source/linear-algebra/source/01-LE/03.ptx
@@ -111,7 +111,7 @@ How many solutions must this system have?
-
+
A = [ 3 -2 13 6
2 -2 10 2
@@ -182,7 +182,7 @@ How many solutions must this system have?
-
+
rref([3,-2,13,6;2,-2,10,2;-1,0,-3,1;3,7,0,-2])
@@ -251,7 +251,7 @@ How many solutions must this system have?
-
+
@@ -399,7 +399,7 @@ different solutions. We'll learn how to find such solution sets in
-
+
diff --git a/source/linear-algebra/source/01-LE/04.ptx b/source/linear-algebra/source/01-LE/04.ptx
index 7af85e7b3..763cd234e 100644
--- a/source/linear-algebra/source/01-LE/04.ptx
+++ b/source/linear-algebra/source/01-LE/04.ptx
@@ -188,7 +188,7 @@ in the following set-builder notation.
-
+
diff --git a/source/linear-algebra/source/02-EV/01.ptx b/source/linear-algebra/source/02-EV/01.ptx
index cbcd8876b..0f1cfb78c 100644
--- a/source/linear-algebra/source/02-EV/01.ptx
+++ b/source/linear-algebra/source/02-EV/01.ptx
@@ -182,7 +182,7 @@ we refer to this real number as a scalar.
-
+
Correct the SageMath code cell below to generate
an illustration of several vectors belonging to
\vspan\left\{\left[\begin{array}{c}1\\2\end{array}\right],
@@ -191,43 +191,53 @@ we refer to this real number as a scalar.
b\left[\begin{array}{c}-1\\1\end{array}\right]}{a, b \in \IR}
in the xy plane.
-
+
-
+
Based on this illustration, which of these geometrical objects
best describes the span of these two vectors?
+
+
+ Which of these geometrical objects
+ best describes the span of these two vectors?
+
A line
A plane
A parabola
A circle
-
-
+
Sketch a representation of all the vectors belonging to
\vspan\left\{\left[\begin{array}{c}6\\-4\end{array}\right],
\left[\begin{array}{c}-3\\2\end{array}\right]\right\}
in the xy plane, or adapt the code in the previous
activity to illustrate this span.
+
+ Sketch a representation of all the vectors belonging to
+ \vspan\left\{\left[\begin{array}{c}6\\-4\end{array}\right],
+ \left[\begin{array}{c}-3\\2\end{array}\right]\right\}
+ in the xy plane.
+
Which of these geometrical objects
best describes the span of these two vectors?
-
@@ -351,7 +361,7 @@ The following are all equivalent statements:
-->
-
+
@@ -376,7 +386,7 @@ The following are all equivalent statements:
-->
-
+
-
diff --git a/source/linear-algebra/source/02-EV/04.ptx b/source/linear-algebra/source/02-EV/04.ptx
index 1c7032283..4fc70f884 100644
--- a/source/linear-algebra/source/02-EV/04.ptx
+++ b/source/linear-algebra/source/02-EV/04.ptx
@@ -319,7 +319,7 @@ which isn't what was asked about.
-
+
@@ -369,7 +369,7 @@ which isn't what was asked about.
-
+
@@ -431,7 +431,7 @@ which isn't what was asked about.
-
+
@@ -474,28 +474,6 @@ which isn't what was asked about.
-
diff --git a/source/linear-algebra/source/02-EV/05.ptx b/source/linear-algebra/source/02-EV/05.ptx
index bdef470e9..65f7430eb 100644
--- a/source/linear-algebra/source/02-EV/05.ptx
+++ b/source/linear-algebra/source/02-EV/05.ptx
@@ -520,7 +520,7 @@ Not a basis, because not only does it fail to span \IR^4, it's also linea
-
+
diff --git a/source/linear-algebra/source/02-EV/06.ptx b/source/linear-algebra/source/02-EV/06.ptx
index cfe6e05f2..6bd2a191e 100644
--- a/source/linear-algebra/source/02-EV/06.ptx
+++ b/source/linear-algebra/source/02-EV/06.ptx
@@ -204,7 +204,7 @@ T=\left\{
-
+
diff --git a/source/linear-algebra/source/02-EV/07.ptx b/source/linear-algebra/source/02-EV/07.ptx
index b97f62ea5..9181bdd55 100644
--- a/source/linear-algebra/source/02-EV/07.ptx
+++ b/source/linear-algebra/source/02-EV/07.ptx
@@ -196,7 +196,7 @@ is already linearly independent and therefore already a basis for the subspace.
-
+
@@ -238,7 +238,7 @@ Find a basis for this solution space.
-
+
@@ -327,7 +327,7 @@ vector cannot be independent.
-
+
@@ -373,7 +373,7 @@ shape of the data that gets projected onto this single point of the screen?
-
+
diff --git a/source/linear-algebra/source/03-AT/02.ptx b/source/linear-algebra/source/03-AT/02.ptx
index 6e214ad0b..6df2c1327 100644
--- a/source/linear-algebra/source/03-AT/02.ptx
+++ b/source/linear-algebra/source/03-AT/02.ptx
@@ -501,7 +501,7 @@ to the variable v, then compute A*v.
-
+
format rat
A = [
@@ -553,7 +553,7 @@ T\left(\left[\begin{array}{c} -2 \\ 5 \end{array}\right]\right)
-
+
@@ -574,7 +574,7 @@ T\left(\left[\begin{array}{c} -2 \\ 5 \end{array}\right]\right)
-
+
format rat
A = [
diff --git a/source/linear-algebra/source/03-AT/03.ptx b/source/linear-algebra/source/03-AT/03.ptx
index bb0bcb58b..37b39accc 100644
--- a/source/linear-algebra/source/03-AT/03.ptx
+++ b/source/linear-algebra/source/03-AT/03.ptx
@@ -209,7 +209,7 @@ Let T: \IR^3 \rightarrow \IR^2 be the linear transformation with the foll
-
+
@@ -247,7 +247,7 @@ Find a basis for the kernel of T.
-
+
@@ -503,7 +503,7 @@ In general, an arbitrary vector \left[\begin{array}{c}\unknown\\\unknown\\\un
-
+
@@ -589,7 +589,7 @@ Find a basis for the kernel and a basis for the image of T.
-
+
@@ -696,7 +696,7 @@ The dimension of the image is called the rank of T (or A<
-->
-
+
@@ -770,7 +770,7 @@ Given a matrix M
-
+
@@ -791,7 +791,7 @@ Given a matrix M
-
+
@@ -813,7 +813,7 @@ Are the row space and column space of N both equal to \mathbb{R}^3
-
+
diff --git a/source/linear-algebra/source/03-AT/04.ptx b/source/linear-algebra/source/03-AT/04.ptx
index 33609a6ff..76555c1ca 100644
--- a/source/linear-algebra/source/03-AT/04.ptx
+++ b/source/linear-algebra/source/03-AT/04.ptx
@@ -897,7 +897,7 @@ Which of the following must be true?
-
+
rref([2,1,-1; 4,1,1; 6,2,1])
@@ -921,7 +921,7 @@ Which of the following must be true?
-
+
rref([2,1,-1; 4,1,1; 6,2,0])
@@ -945,7 +945,7 @@ Which of the following must be true?
-
+
rref([2,3;1,-1;1,3])
@@ -969,7 +969,7 @@ Which of the following must be true?
-
+
rref([2,1,-1;4,1,1])
diff --git a/source/linear-algebra/source/04-MX/01.ptx b/source/linear-algebra/source/04-MX/01.ptx
index 58a53dfd4..cefa76b2c 100644
--- a/source/linear-algebra/source/04-MX/01.ptx
+++ b/source/linear-algebra/source/04-MX/01.ptx
@@ -261,7 +261,7 @@ B*A
-
+
B = [3 -4 0 ; 2 0 -1 ; 0 -3 3]
A = [2 7 -1 ; 0 3 2 ; 1 1 -1]
diff --git a/source/linear-algebra/source/04-MX/02.ptx b/source/linear-algebra/source/04-MX/02.ptx
index 14fe9c8eb..59ebf327e 100644
--- a/source/linear-algebra/source/04-MX/02.ptx
+++ b/source/linear-algebra/source/04-MX/02.ptx
@@ -38,7 +38,7 @@
-
+
@@ -191,7 +191,7 @@ T^{-1}(\vec e_2)\hspace{1em}T^{-1}(\vec e_3)]
-
+
@@ -251,7 +251,7 @@ Let T\colon\IR^4\to\IR^4 be the linear bijection given by the standard ma
-
+
@@ -278,7 +278,7 @@ Is the matrix \left[\begin{array}{ccc} 2 & 3 & 1 \\ -1 & -4 &
-
+
@@ -316,7 +316,7 @@ Is the matrix \left[\begin{array}{ccc} 2 & 3 & 1 \\ -1 & -4 &
-
+
diff --git a/source/linear-algebra/source/04-MX/03.ptx b/source/linear-algebra/source/04-MX/03.ptx
index 582acd20e..6608f4e42 100644
--- a/source/linear-algebra/source/04-MX/03.ptx
+++ b/source/linear-algebra/source/04-MX/03.ptx
@@ -33,7 +33,7 @@
-
+
@@ -204,7 +204,7 @@
Calculate M_{\mathcal{B}}=B^{-1} using technology.
-
+
@@ -313,7 +313,7 @@ but where inputs and outputs are all given in \mathcal B-coordinates?
Calculate the matrix M_\mathcal{B}AM_{\mathcal{B}}^{-1}.
-
+
diff --git a/source/linear-algebra/source/04-MX/04.ptx b/source/linear-algebra/source/04-MX/04.ptx
index d7314f6b5..fbb07005c 100644
--- a/source/linear-algebra/source/04-MX/04.ptx
+++ b/source/linear-algebra/source/04-MX/04.ptx
@@ -184,7 +184,7 @@ the first row when left-multiplying? (R_1+5R_3\to R_1)
-
+
@@ -313,7 +313,7 @@ Check your work using technology.
-
+
@@ -364,7 +364,7 @@ Check your work using technology.
-
+
diff --git a/source/linear-algebra/source/04-MX/samples/01.ptx b/source/linear-algebra/source/04-MX/samples/01.ptx
index c88ac742d..6b7589946 100644
--- a/source/linear-algebra/source/04-MX/samples/01.ptx
+++ b/source/linear-algebra/source/04-MX/samples/01.ptx
@@ -29,7 +29,7 @@ Of the following three matrices, only two may be multiplied.
Find their product using technology.
-
+
A = [
-1 3 -2 -3
diff --git a/source/linear-algebra/source/04-MX/samples/04.ptx b/source/linear-algebra/source/04-MX/samples/04.ptx
index 462b4f890..e3eb6e439 100644
--- a/source/linear-algebra/source/04-MX/samples/04.ptx
+++ b/source/linear-algebra/source/04-MX/samples/04.ptx
@@ -53,7 +53,7 @@
\sim\left[\begin{array}{ccc} -5 & 15 & 15 \\ 2 & -6 & -5 \\ -4 & 12 & 12 \end{array}\right]
\sim\left[\begin{array}{ccc} -4 & 12 & 12 \\ 2 & -6 & -5 \\ -5 & 15 & 15 \end{array}\right]
-
+
C = [
-5 0 0
diff --git a/source/linear-algebra/source/05-GT/02.ptx b/source/linear-algebra/source/05-GT/02.ptx
index 4fd315b0b..1b65303c7 100644
--- a/source/linear-algebra/source/05-GT/02.ptx
+++ b/source/linear-algebra/source/05-GT/02.ptx
@@ -411,7 +411,7 @@ Based on the previous activities, which technique is easier for computing determ
-You can check your answers using technology.
+
You can check your answers using technology.
det([4,-3,0,0; 1,-3,2,-1; 3,2,0,3; 0,-3,2,-2])
diff --git a/source/linear-algebra/source/05-GT/04.ptx b/source/linear-algebra/source/05-GT/04.ptx
index cd38ec074..b833b903e 100644
--- a/source/linear-algebra/source/05-GT/04.ptx
+++ b/source/linear-algebra/source/05-GT/04.ptx
@@ -52,7 +52,7 @@ to find all the eigenvectors \vec x such that A\vec x=-2\vec x.
-
+
@@ -80,7 +80,7 @@ associated with the eigenvalue 3.
-
+
@@ -97,7 +97,7 @@ associated with the eigenvalue 1.
-
+
@@ -116,7 +116,7 @@ associated with the eigenvalue 2.
-
+