グラフは問題集1 p.131 (1) y=log2(x+2)x軸に−2平行移動y = \log_2(x+2) \qquad x \text{軸に} -2 \text{平行移動}y=log2(x+2)x軸に−2平行移動 (2) y=log2(−x)y軸対称y = \log_2(-x) \qquad y \text{軸対称}y=log2(−x)y軸対称 (3) y=log12x=log2xlog212=−log2xx軸対称y = \log_{\frac{1}{2}} x = \dfrac{\log_2 x}{\log_2 \frac{1}{2}} = -\log_2 x \qquad x \text{軸対称}y=log21x=log221log2x=−log2xx軸対称 (4) y=log24x=log24+log2x=2+log2xy軸に2平行移動y = \log_2 4x = \log_2 4 + \log_2 x = 2 + \log_2 x \qquad y \text{軸に} 2 \text{平行移動}y=log24x=log24+log2x=2+log2xy軸に2平行移動 (5) y=log21x=−log2xx軸対称y = \log_2 \dfrac{1}{x} = -\log_2 x \qquad x \text{軸対称}y=log2x1=−log2xx軸対称