This semester, I did my School Experience Program (SEP) in SMA Labschool
Kebayoran. The objective of SEP for this semester was experiencing the teaching
for at least four times alone by myself (not for peer-teaching any longer).
Moreover, the course embedded to this program was Project Based Learning in
Mathematics Instruction (PjBLMI), so I should apply the PjBL in my teachings.
The topic assigned by my master teacher was Trigonometry, so the PjBL
should relate to it. I chose to apply the PjBL in my third teaching. At that
time, the sub-topic was graphing the trigonometric function. I designed the
project worksheet and introduced the basic graph of Sine, Cosine, and Tangent
on the worksheet. I gave them blank table for Sine, Cosine, and Tangent, so
they could fill the blank table with the angles and the value of the function.
Look at this table!
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x =
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...˚
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...˚
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...˚
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...˚
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...˚
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...˚
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...˚
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...˚
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y= sin(x)
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y= cos(x)
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y= tan(x)
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For
example if they wrote 30˚, so they would write ½ for the sin(x), ½ V3 for cos(x), and V3/3 for tan(x). Moreover, I asked them to plot the (x ,
y) in the Cartesian coordinate provided, and connect the points to make a
graph.
I chose the basic function of sin(x), cos(x), and tan(x) because I
wanted them to feel familiar with the graph of trigonometric function and I also
to differentiate each graph. So, if they had understood to distinguish each
kind of trigonometric graph, they could guess the given graphs of function when
they face the test.
After they were given the basic graph of trigonometric function, I
guided them to make another graph of function, such as 2sin(x), sin(x)+2,
-sin(2x), ½.cos(x), cos(x)–2, -cos(½.x), tan(2x), and 2tan(x). The purpose of
this is the students can distinguish the graph if the function is multiplied by
any constant, if the angle of the function is multiplied by any constant, and
if the function is added by any constant.
When I gave them the examples (the basic function of the trigonometric
function) they just reacted as usual. They just found that the graph of sine
and cosine are somewhat similar, while the graph of tangent is different and is
quite hard to graph. However, after they graph another function, they found
that it was easy to graph another function if they were familiar with the basic
function. Next, I asked them to conclude about graphing the general function of
y = a.sin(bx)+c, y = a.cos(bx)+c, and y = a.tan(x)+c. So, I felt that I was
success to guide them in graphing the trigonometric function and
differentiating each kind of them.
If I teach the same lesson again, I will not change my examples because
I think that giving the basic function is the most appropriate lesson to be
given to the students. After we give the basic, we can manipulate the function
(in this case is trigonometric function) by multiplying it with any constant,
and then we can manipulate it by multiplying the angles by any constant, also
we can manipulate it by adding with any constant. In the end of the lesson, we
can guide them to conclude about the most general form of the function, and
then graph it, and then differentiate each kind of them. All in all, I decided
to use the same examples if I am assigned to teach the same lesson again.
