水平方向：S=VcosCt+1/2At^2.1

豎直方向：H=VsinCt+1/2Gt^2.2

1*H-2*S得：

Vt(HcosC-SsinC)+1/2t^2(AH-GS)=0.3

3兩邊同時除以t^2得：

V/t(HcosC-SsinC)+1/2(AH-GS)=0

V/t=(GS-AH)/2(HcosC-Ssinc)

t=2V(HcosC-Ssinc)/(GS-AH).4

4帶入2得：

H=[2sinC(HcosC-Ssinc)/(GS-AH)]V^2+2G[(HcosC-Ssinc)/(GS-AH)]^2V^2

V^2={[2sinC(HcosC-Ssinc)/(GS-AH)]+2G[(HcosC-Ssinc)/(GS-AH)]^2}/H

V={[2sinC(HcosC-Ssinc)/(GS-AH)]+2G[(HcosC-Ssinc)/(GS-AH)]^2}/H開根號

願意的話自己化簡吧.

如果H=0,VsincC就是負的方程是一樣的；化簡不一樣而已.如果你連這種化解都不願意做,就不要問我了!我沒空.

至於A是負值怎麼會無解?S也可能為負.如果無解就表明題目條件本生就有誤,所以無解.