Prove if y=arcsin x has the range -pi/2 .....pi/2 implies that cos x >/= 0?

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  • 4 weeks ago

    it s obvious  but it is about derivative: y'= 1/1-x^2, book says : ignore negative sign because cos x is always positive (-pi/2....pi/2)

  • 4 weeks ago

    (Ted S's answer ducks the issue, and thus is correct; but) it should be  cos y ≥ 0 .

  • ted s
    Lv 7
    4 weeks ago

    comment ; a domain of [ - π / 2 , π / 2 ] has cosine ≥ 0.......alt242 for ≥ symbol

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