If tan(x+10°)=cot(3x-20°), what is the value of x?
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Correct answer: B
Explanation
Has been given :
tan(x + 10°) = cot(3x − 20°)
According to the formula:
cot θ = tan(90° − θ)
tan(x + 10°) = tan(90° − (3x − 20°))
= tan(110° − 3x)
Therefore
x + 10 = 110 − 3x
4x = 100
x = 25°