Casio fx-350MS - Circular Measure

CHAPTER 4 Circular Measure
13
MODE
2
1
2
6
0
SHIFT
a
b
/
c
X
2
X
1
1
2
2
x
2
SHIFT
a
b
/
c
X
0
sin
X
6
DGRÈ
Ans
1
RCL
–
M+
=
=
=
MODE
M+
DGRÈ
Ans
0
STO
RCL
M
M
+
SHIFT
x
2
AOB is a sector of a circle with centre at O and radius 2cm. Find the area
of the shaded region.
OPERATION
1. First enter Rad (radian) mode.
2. Calculate the area of sector using the formula
θ
2
2
1
r
and store the calculated result.
3. Now calculate the area of the triangle AOB using the formula
θsin
2
1
2
r
.
4. The area of the shaded region is
Therefore, the area of shaded region is approximately 0.3623cm
2
, ignoring the negative
sign.
Show that the length of arc AB in the above example is approximately 2.0944cm.
Press to clear the memory stored in M.
Exam
p
le 1
R
0
1ª2X2
2
X sin 60–
1.732050808
Ans-M
-0.362344294
A
O
60°
B
2cm
2cm
1ª2X 60– X2
2
2.09439510
2