108學年度身心障礙學生升學大專校院甄試試題
解:$$\begin{cases} a>0 \Rightarrow ax^3+b >x^2,當x\to\infty\\ a<0 \Rightarrow ax^3+b>x^2,當x\to -\infty\end{cases} \Rightarrow a=0\\
甄試類(群)組別:大學組
考試科目(編號):數學甲
單選題,共 20 題,每題 5 分又,當x=0 \Rightarrow x^2> ax^3+b \Rightarrow 0>b\\
因此(a=0,b<0),故選\bbox[red,2pt]{(D)} $$
解:
$$\overline{AO}=1 \Rightarrow \begin{cases}A(1) \Rightarrow \begin{cases} B(3)\Rightarrow \begin{cases} C(6)\\ C(0) \end{cases}\\ B(-1)\Rightarrow \begin{cases} C(2)\\ C(-4) \end{cases} \end{cases}\\ A(-1) \Rightarrow \begin{cases} B(1) \Rightarrow \begin{cases} C(4)\\ C(-2) \end{cases}\\ B(-3) \Rightarrow \begin{cases} C(0)\\ C(-6) \end{cases}\end{cases} \end{cases} \Rightarrow (A,B,C)= \begin{cases} (1,3,6)\\ (1,3,0)\\ (1,-1,2)\\ (1,-1,-4)\\ (-1,1,4)\\(-1,1,-2)\\ (-1,-3,0)\\ (-1,-3,-6) \end{cases} \\ \Rightarrow C=0,2,4,6,-2,-4,-6\Rightarrow 有7種可能,故選\bbox[red,2pt]{(C)}$$
解:$$ \begin{cases} f(x)=p(x)(x-1)(x-2)+(2x-2)\\ f(x)=q(x)(x-2)(x-3)+(ax+2) \end{cases} \Rightarrow \begin{cases} f(2)=0+(4-2)=2\\ f(2)=0+(2a+2) \end{cases} \Rightarrow 2a+2=2 \Rightarrow a=0\\
令f(x)=r(x)(x-1)(x-3)+(bx+c)\Rightarrow \begin{cases} f(1)=b+c=0+(2-2)=0\\ f(3)=0+(3b+c)=0+(3a+2)=2 \end{cases}\\ \Rightarrow \begin{cases} b+c=0\\ 3b+c=2 \end{cases} \Rightarrow \begin{cases} b=1\\ c=-1 \end{cases} \Rightarrow 餘式: bx+c=x-1,故選\bbox[red,2pt]{(A)}$$
解:
$$由題意可知\begin{cases} A=(1,1)\\ B=(1/2,1)\\ C=(2,2)\\ D=(1,2) \end{cases} \Rightarrow ABDC面積= {(\overline{AB}+\overline{CD})\times dist(L,M) \over 2}={(1/2+1)\times 1\over 2}={3\over 4}\\,故選\bbox[red,2pt]{(A)}$$
解:$$ \begin{cases} 2x+3y=11\\ 2x-5y=3 \end{cases} \Rightarrow \begin{cases} x=4\\ y=1 \end{cases} \Rightarrow 圓心O=(4,1) \Rightarrow 圓半徑r=圓心O至3x+4y=6的距離 \\ \Rightarrow r=\left|{ 12+4-6\over \sqrt{3^2+4^2}} \right| ={10\over 5}=2 \Rightarrow 圓方程式(x-4)^2+(y-1)^2=2^2,故選\bbox[red,2pt]{(D)}$$
解:$$ \begin{cases} x-y+z=0\\ x+2y+z=3\\x+y=4 \end{cases} \Rightarrow \left[\begin{array}{rrr|r}1&-1&1&0\\1 & 2& 1 & 3\\ 1& 1 & 0 &4 \end{array} \right] \xrightarrow{-r_1+r_2\;,-r_1+r_3} \left[\begin{array}{rrr|r}1&-1&1&0\\0 & 3& 0 & 3\\ 0& 2 & -1 &4 \end{array} \right] \\\xrightarrow{r_2/3} \left[\begin{array}{rrr|r}1&-1&1&0\\0 & 1& 0 & 1\\ 0& 2 & -1 &4 \end{array} \right] \xrightarrow{r_2+r_1, -2r_2+r_3}\left[\begin{array}{rrr|r}1& 0& 1 &1\\0 & 1& 0 & 1\\ 0& 0 & -1 &2 \end{array} \right] \\\xrightarrow{r_3+r_1}\left[\begin{array}{rrr|r}1& 0& 0 &3\\0 & 1& 0 & 1\\ 0& 0 & -1 &2 \end{array} \right] \xrightarrow{-r_3}\left[\begin{array}{rrr|r}1& 0& 0 &3\\0 & 1& 0 & 1\\ 0& 0 & 1 & -2 \end{array} \right],故選\bbox[red,2pt]{(C)}$$
解:$$\theta=\angle DAB \Rightarrow 2\theta =\angle A\Rightarrow \cos{2\theta} =\cos{\angle A}={\overline{AC}^2 +\overline{AB}^2-\overline{BC}^2 \over 2\overline{AC}\cdot\overline{AB}} = {10^2+5^2- 12^2\over 2\cdot 10\cdot 5} = -{19\over 100} \\ \Rightarrow \cos{2\theta} =-{19 \over 100}=2\cos^2{\theta}-1 \Rightarrow \cos^2{\theta}={81 \over 200} \Rightarrow \cos{\theta}= {9\over 10\sqrt{2}} = {9\sqrt{2} \over 20},故選\bbox[red,2pt]{(B)}$$
解:$${1\over 6}(200+500+1000+0+200+500) = {1\over 6}\times 2400=400,故選\bbox[red,2pt]{(B)}$$
解:$$M=\begin{bmatrix}a&b\\ c&d \end{bmatrix} \Rightarrow \begin{cases} M\begin{bmatrix}1\\ 2 \end{bmatrix} = \begin{bmatrix} 2\\ 1 \end{bmatrix} \\ M\begin{bmatrix}2 \\ 1 \end{bmatrix} = \begin{bmatrix} 4\\ 2 \end{bmatrix}\end{cases} \Rightarrow \begin{cases} \begin{bmatrix}a&b\\ c&d \end{bmatrix}\begin{bmatrix}1\\ 2 \end{bmatrix} = \begin{bmatrix} 2\\ 1 \end{bmatrix} \\ \begin{bmatrix}a&b\\ c&d \end{bmatrix}\begin{bmatrix}2 \\ 1 \end{bmatrix} = \begin{bmatrix} 4\\ 2 \end{bmatrix}\end{cases} \Rightarrow \begin{cases} a+2b=2\\ c+2d=1 \\2a+b=4 \\ 2c+d=2 \end{cases}\Rightarrow \begin{cases} a=2\\ b=0 \\ c=1 \\ d=0 \end{cases}\\ \Rightarrow M=\begin{bmatrix}2 &0\\ 1& 0 \end{bmatrix} \Rightarrow \begin{bmatrix}-1 &1\\ -1& 1 \end{bmatrix}M\begin{bmatrix} -1\\ 1 \end{bmatrix} = \begin{bmatrix}-1 &1\\ -1& 1 \end{bmatrix} \begin{bmatrix}2 &0\\ 1& 0 \end{bmatrix}\begin{bmatrix} -1\\ 1 \end{bmatrix} =\begin{bmatrix}-1 &0\\ -1& 0 \end{bmatrix} \begin{bmatrix} -1\\ 1 \end{bmatrix} =\begin{bmatrix} 1\\ 1 \end{bmatrix}\\,故選\bbox[red,2pt]{(C)} $$
解:$$L: y=mx+b \Rightarrow \begin{cases}L過(1,3)\\ d(O,L)=3 \end{cases} \Rightarrow \begin{cases}3=m+b\\ \left|{b\over \sqrt{m^2+1}} \right|=3 \end{cases} \Rightarrow \left|{3-m\over \sqrt{m^2+1}} \right|=3 \Rightarrow (m-3)^2=9(m^2+1) \\ \Rightarrow 8m^2+6m=0 \Rightarrow m(4m+3)=0 \Rightarrow m=-{3\over 4},0(不合,\because L不平行X軸),故選\bbox[red,2pt]{(D)}$$
解:$$\vec{u}\cdot \vec{v}=5 \Rightarrow (1,-2,2)\cdot(a,b,0)=a-2b=5 \Rightarrow a^2+b^2 =(2b+5)^2 +b^2= 5b^2+20b +25\\ = 5(b^2+4b+4)+5 =5(b+2)^2+5 \Rightarrow b=-2時, a^2+b^2有最小值5\\ \Rightarrow |\vec{v}|=\sqrt{a^2+b^2}的最小值為=\sqrt{5},故選\bbox[red,2pt]{(A)}$$
解:$${甲不拿A且乙拿B \over 甲不拿A} = {C^4_2C^3_2 \over C^5_2C^4_2C^2_2} = {6\times 3 \over 10\times 6} ={18\over 60} ={3\over 10},故選\bbox[red,2pt]{(D)}$$
解:
$$餘弦定理\Rightarrow \cos{\angle COA}={\overline{AO}^2 +\overline{CO}^2-\overline{AC}^2 \over 2\overline{AO}\times \overline{CO}} = {10+10-16 \over 20} ={1\over 5}\\ \Rightarrow \sin{\angle BOC} =\cos{\angle COA} ={1\over 5},故選\bbox[red,2pt]{(A)}$$
解:$$|\vec{a}||\vec{b}|\sin{\theta} =15^2\times {7\over 25}=63,故選\bbox[red,2pt]{(B)}$$
解:$$L:\begin{cases} x=1+t\\ y=-1-2t\\ z=3+2t \end{cases} \Rightarrow L的方向向量\vec{u}=(1,-2,2)
\\ 假設平面的法向量為\vec{n},若平面與L不相交,則\vec{u}\cdot\vec{n}=0,且L不在平面上\\
(A) \vec{n}=(2,2,1) \Rightarrow \vec{u}\cdot \vec{n}=0, 但2(1+t)+2(-1-2t)+(3+2t)=3\Rightarrow L在平面上\\
(B)\vec{n}=(2,-1,-2) \Rightarrow \vec{u}\cdot \vec{n}=0, 且2(1+t)-(-1-2t)-2(3+2t)=-3\ne 3\Rightarrow L不在平面上\\
(C)\vec{n}=(2,2,-1) \Rightarrow \vec{u}\cdot \vec{n}= 2-4-2=-4\ne 0\\
(D)\vec{n}=(2,1,-1) \Rightarrow \vec{u}\cdot \vec{n}=2-2-2=-2\ne 0,\\故選\bbox[red,2pt]{(B)}$$
解:$$\text{實際支持甲的比率為 }p \Rightarrow \text{實際不支持甲的比率為 }1-p \Rightarrow p(1-0.1)+(1-p)\times 0.3=0.54\\ \Rightarrow 0.3+0.6p=0.54 \Rightarrow p=0.4,故選\bbox[red,2pt]{(C)}$$
解:$$\log{E(r)}=5.24+1.44r \Rightarrow \log{E(6)}=5.24+1.44\times 6= 13.88 \Rightarrow E(6)=10^{13.88}\\
\Rightarrow 100\times 10^{13.88} = 10^{15.88} \Rightarrow \log{E(a)} = 15.88 =5.24+1.44\times a \Rightarrow a={15.88-5.24 \over 1.44} \approx 7.39\\,故選\bbox[red,2pt]{(B)}$$
解:$$f(x)=-\sqrt{3}\cos{x} +\sqrt{6}\sin{x}-2 = -3\left({\sqrt{3} \over 3}\cos{x} -{\sqrt{6}\over 3} \sin{x}\right) -2 \\= -3\left(\sin{y}\cos{x} -\cos{y} \sin{x}\right) -2 = -3\sin{(y-x)}-2 \Rightarrow -3-2\le f(x)\le 3-2 \\\Rightarrow -5 \le f(x)\le 1 \Rightarrow f(x)最大值為1,故選\bbox[red,2pt]{(A)}$$
解:$$\begin{cases} f(x)=a\cdot 2^{bx}為凹口向下 \Rightarrow a<0;\\ f(-1)>f(0) \Rightarrow a\cdot 2^{-b}> a \Rightarrow 2^{-b}<1 \Rightarrow b>0 \end{cases} \Rightarrow \begin{cases} a<0\\ b>0 \end{cases},故選\bbox[red,2pt]{(C)}$$
解:$$z=\sqrt{2}\left(\cos{\pi \over 12}+i\sin{\pi \over 12} \right) \Rightarrow z^6= (\sqrt{2})^6\left(\cos{\pi \over 12}\times 6+i\sin{\pi \over 12}\times 6 \right) =8\left(\cos{\pi \over 2}+i\sin{\pi \over 2} \right)\\ =8(0+i)= 8i,故選\bbox[red,2pt]{(D)}$$
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