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Solved Examples
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Review Test on Analyzing Data
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Next>>
Attempt following question by selecting a choice to answer.
D
Using double-angle formulas, choose the formula that corresponds to the value of
cot 4A.
B D
A.
D
4cot A
B.
D
cot
2
2
A
+
1
2
cot
2
A
C.
D
cot
2
2
A
-
1
2
cot
2
A
D.
D
2cot 2A
D
C
View Solution Steps
Step 1: cot 4A =
cos
4
A
sin
4
A
Step 2: =
cos
2
(
2
A
)
sin
2
(
2
A
)
Step 3: =
cos
2
2
A
-
sin
2
2
A
2
sin
2
A
cos
2
A
[Use cos 2
θ
= cos
2
θ
- sin
2
θ
and sin 2
θ
= 2sin
θ
cos
θ
.]
Step 4: =
cos
2
2
A
sin
2
2
A
-
sin
2
2
A
sin
2
2
A
2
sin
2
A
cos
2
A
sin
2
2
A
[Divide numerator and denominator with sin
2
2A.]
Step 5: =
cot
2
2
A
-
1
2
cot
2
A
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