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Today's Calculation Of Integral
2007 Today's Calculation Of Integral
208
208
Part of
2007 Today's Calculation Of Integral
Problems
(1)
Today's caluculation of Integral 208
Source: Waseda University entrnace exam/Education 1979
5/31/2007
Find the values of real numbers
a
,
b
a,\ b
a
,
b
for which the function
f
(
x
)
=
a
∣
cos
x
∣
+
b
∣
sin
x
∣
f(x)=a|\cos x|+b|\sin x|
f
(
x
)
=
a
∣
cos
x
∣
+
b
∣
sin
x
∣
has local minimum at
x
=
−
π
3
x=-\frac{\pi}{3}
x
=
−
3
π
and satisfies
∫
−
π
2
π
2
{
f
(
x
)
}
2
d
x
=
2
\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}}\{f(x)\}^{2}dx=2
∫
−
2
π
2
π
{
f
(
x
)
}
2
d
x
=
2
.
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