sor原來寫錯左sin cos 應該係30度
let k be mid point of bd
ab=x and bc =sqrt3x
bk=ksin60=sqrt3x/2
sinacb=bk/bc=1/2
acb=30
不過做到後面好似有啲幾奇怪既result 唔知有冇錯
或者就這樣吧2020-04-05 15:41:06
原來份卷寫漏左 cad=60唔怪得之
銀影2020-04-05 16:16:17
或者就這樣吧2020-04-05 16:22:26
佢寫左係第二張紙到 我做完都唔記得左sorry
迎賓接福2020-04-05 17:39:36
thanks試咗計唔知計得啱唔啱
a. (x + 1/2)^2 - 1/4
b. i. 30°, ii. (sqrt3)x/2 cm
c. i. as AN⟂BY, agree
ii. note that theta = DYC
DYC=theta=180°, 2D, so phi=180°
product=(-1)(-1)=1
DYC=theta=90°, product直接=0
so decrease from 1 to 0
d. 160