Question

高中数学，这题怎么做？

第六题

Answer 1

这位同学，y=√2(sin2x+cos2x)=2sin(2x+兀/4)，根据三角函数“左加右减，上加下减”的平移方法，只需要把y=2sin2x向左平移兀/8个单位即可，也就是y=2sin2(x+兀/8)=2sin(2x+兀/4)，希望帮助到你!

Answer 2

y=√2(sin2x+cos2x)
=2*√2/2(sin2x+cos2x)
=2*(sin2x *√2/2 +cos2x *√2/2)
=2*(sin2x *cos(π/4) +cos2x*sin(π/4))
=2sin(2x+π/4)
=2sin[2(x+π/8)]
根据左加右减，y=2sin2x变为上述形状
是向左平移π/8，所以B正确

Answer 3

解，y=√2(sin2x+cos2x)=2sin(2x+π/4)
则y=2sin(2x)向左移π/8，得y=2sin(2(x+π/8))
=2sin(2x+π/4)
选B