quick inverse trig question (1 Viewer)

kooltrainer

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(tan inverse 2/root3 ) - ( tan inverse 3/2root3) = tan inverse root3 /12
 

Trebla

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Let A = tan<sup>-1</sup>(2 / √3) and B = tan<sup>-1</sup>(3 / 2√3)
=> tan A = 2 / √3
=> tan B = 3 / 2√3

We know that:
tan (A - B) = [tan A - tan B] / [1 + tan A.tan B]
= [2 / √3 - 3 / 2√3] / [1 + 6/6]
= [1 / 2√3] / 2
= 1 / 4√3
= √3 / 12 after rationalising denominator
.: (A - B) = tan<sup>-1</sup>(√3 / 12)
Sub back A and B:
.: tan<sup>-1</sup>(2 / √3) - tan<sup>-1</sup>(3 / 2√3) = tan<sup>-1</sup>(√3 / 12)
 

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