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:
1. 42
2. 6
3. 18
4. 0
5. - 2
Step-by-step explanation:
Use BIDMAS
Answer:
x=1 y = -1/2
(1,-1/2)
Step-by-step explanation:
7x-2y=8
5x+2y=4
I would use elimination since we have 2y in one equation and -2y in the other
7x-2y=8
5x+2y=4
--------------------
12x = 12
Divide each side by 12
12x/12 = 12/12
x =1
The substitute back into equation 2
5(1) +2y = 4
5 +2y = 4
Subtract 5
5-5+2y = 4-5
2y = -1
Divide by 2
2y/2 = -1/2
y = -1/2
400 lbs = 0.2 tons
38,600 mg = 3.86 dekagrams
Hope it helps!
Answer:
(i) Lowest Temperature: Warsaw
Highest Temperature: Cairo
(ii) 27.1 + 35.2 = 62.3°C
