a.math

If cos θ and cosec θ are the two roots of the equation 3x^2 + hx -1 =0, where π/2 < θ< π, find the value(s) of h and leave your answer in surd form.
cos θ+ cosecθ=-h/3...(1)
(cos θ)(cosecθ)=-1/3...(2)
because cosecθ=1/sinθ
we get cotθ=-1/3 ,tanθ=-3
cosθ=-1/√10 and sinθ=3/√10
-h/3
=cos θ+ cosecθ
=cos θ+ 1/sinθ
=-1/√10+ √10/3
=(-3+10)/(3√10)
=7/(3√10)
h=-7√/10
條題目都說 leave your answer in surd form﹐h有99%係有開方根的。