2021-II-37
Ans: B
… Read For any real number $x$, $x^2+kx+k+8\ge 0$. Then we ha
HKDSE-MATH
2021-II-38
Ans: B
… Read Add a point $X$ on $CD$ such that $EX \perp CD$. Hence, $
2021-II-39
Ans: D
… Read Join $AD$.
In $\Delta CDE$,
$\begin{array}{rcll}
\a
2021-II-40
Ans: A
… Read $\left\{ \begin{array}{l}
x^2 +y^2 -4x -22y +75 = 0 &#
2021-II-41
Ans: C
… Read Let $Q=(x,y)$. Denote the orthocentre by $H$. Since $
2021-II-42
Ans: D
… Read The required number of different choirs
$\begin{arr
2021-II-43
Ans: D
… Read The required probability
$\begin{array}{cl}
=
2021-II-44
Ans: C
… Read Let $\sigma$ be the standard deviation of the examina
2021-II-45
Ans: B
… Read Let $a$ and $d$ be the first term and the common differe