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Question
The value of tan 72° tan 18° is
Options
0
1
18°
72°
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Solution
1
Explanation;
Hint:
tan 72° . tan 18° = tan 72° . tan (90° – 72°)
= tan 72° . cot 72°
= `tan 72^circ xx 1/tan 72^circ`
= 1
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