tan2α=-7.12 则tanα=?α=?
问题描述：
tan2α=-7.12 则tanα=?α=?
答
tan2α = 2tanα/(1-tan²α) = -7.12
tan²α - 2tanα/7.12 - 1 = 0
tanα = 1/7.12 ± √(1/7.12² +1)
= 0.14 ± 1.06
α=arctan1.2 或 α=arctan0.92