趣味

\(\sin{(\alpha+\beta)}=\sin{\alpha}\cos{\beta}+\cos{\alpha }\sin{\beta }\)\(\sin{(\alpha-\beta)}=\sin{\alpha}\cos{\beta}...

\(a{x}^{2}+bx+c=0\) \((a\neq 0)\)の解の公式は$$x=\frac{-b\pm\sqrt{{b}^{2}-4ac}}{2a}$$

( 1) \(ma+mb-mc=m(a+b-c)\)( 2) \({a}^{2}+2ab+{b}^{2}={(a+b)}^{2}\)( 3) \({a}^{2}-2ab+{b}^{2}={(a-b)}^{2}\)( 4) \({a}^{2}...

( 1) \({(a+b)}^{2}={a}^{2}+2ab+{b}^{2}\)( 2) \({(a-b)}^{2}={a}^{2}-2ab+{b}^{2}\)( 3) \({(a+b)(a-b)}={a}^{2}-{b}^{2}\)( 4...