来自付明玉的问题
数学题:很简单的转化吧!已知:x+y=√2sin(a+π/4),x-y=√2sin(a-π/4).求证:x^2+y^2=1
数学题:很简单的转化吧!
已知:x+y=√2sin(a+π/4),x-y=√2sin(a-π/4).
求证:x^2+y^2=1
1回答
2020-01-27 00:58
数学题:很简单的转化吧!已知:x+y=√2sin(a+π/4),x-y=√2sin(a-π/4).求证:x^2+y^2=1
数学题:很简单的转化吧!
已知:x+y=√2sin(a+π/4),x-y=√2sin(a-π/4).
求证:x^2+y^2=1
(x+y)^2+(x-y)^2=2sin(a+π/4)^2+2sin(a-π/4)^2=2sin(a+π/4)^2+2cos(a-π/4+π/2)^2=2
=>x^2+y^2=1