Question

ɴ

求解🙏

bd3 +6
如右圖,矩形 ABCD中,AB=3,BC=1。若將此矩形放
在距離為2的兩平行線L,L, 之間,且使A,C分別落在
L,L上,則。角為幾度?
〔搭配單元10] COSE
D90-053
√90-€
sine
60/30
是
B
√√√2
L₁
L₂

Answer 1

✨ Jawaban Terbaik ✨

Chemist

cosθ+(3^0.5)cos(90-θ)=2^0.5
=>cosθ+(3^0.5)sin(θ)=2^0.5
=>cosθ+(3^0.5)(1-cos^2(θ))^0.5=2^0.5
=>cosθ-2^0.5=-(3^0.5)(1-cos^2(θ))^0.5
=>cos^2(θ)-2*(2^0.5)cosθ+2=3-3cos^2(θ)
=>x^2-(8^0.5)x+2=3-3x^2
=>x=(2^0.5+6^0.5)/4

不知道有沒有算錯

ɴ

太感謝了🥹🙏