Answer:
Step-by-step explanation:
L
H
S
=
cos
4
x
=
2
cos
2
(
2
x
)
−
1
=
2
(
cos
(
2
x
)
)
2
−
1
=
2
(
2
cos
2
x
−
1
)
2
−
1
=
2
(
4
cos
4
x
−
4
cos
2
x
+
1
)
−
1
=
8
cos
4
x
−
8
cos
2
x
+
2
−
1
=
8
cos
4
x
−
8
cos
2
x
+
1
=
R
H
S
Again
L
H
S
=
cos
4
x
=
2
cos
2
(
2
x
)
−
1
=
2
(
1
−
2
sin
2
x
)
)
2
−
1
=
2
(
1
−
4
sin
2
x
+
4
sin
4
x
)
−
1
=
2
−
8
sin
2
x
+
8
sin
4
x
−
1
=
8
sin
4
x
−
8
sin
2
x
+
1
=
R
H
S
sin
2
x
+
cos
2
x
=
1
cos
2
x
=
1
−
sin
2
x
substitute in the equation as follows
8
cos
4
x
−
8
cos
2
x
+
1
=
8
cos
2
x
(
cos
2
x
−
1
)
+
1
=
8
(
1
−
sin
2
x
)
(
1
−
sin
2
x
−
1
)
+
1
=
8
(
1
−
sin
2
x
)
(
−
sin
2
x
)
+
1
=
8
sin
4
x
−
8
sin
2
x
+
1
Answer:15
I know Bc I got it wrong that was the answer
Answer:
24.012
Step-by-step explanation:
y=kx^2
54=81k
k=54/81
k=0.667
y=kx^2
y=0.667×36
y=24.012
Let
x--------> original length side of a square
we know that
area rectangle=length*width
area=126 in²
length=(x+8)
width=(x-3)
so
126=(x+8)*(x-3)------> x²-3x+8x-24=126----> x²+5x-150=0
using a graph tool------> to resolve the second order equation
see the attached figure
the solution is
x=10 in
the answer isthe original length side of a square is 10 in