求函数y=sin(x+20)-cos(x-10)的值域y=sin(x+20)-cos(x-10)的值域 我这么做对吗?y=sin(x-10+30) - cos(x-10)y=sin(x-10)cos30 + sin30(x-10) - cos (x-10)y=sin(x-10)cos30 - sin30(x-10)y=sin(x-10-30)y=sin(x-40)所以值域为 -1,1
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![求函数y=sin(x+20)-cos(x-10)的值域y=sin(x+20)-cos(x-10)的值域 我这么做对吗?y=sin(x-10+30) - cos(x-10)y=sin(x-10)cos30 + sin30(x-10) - cos (x-10)y=sin(x-10)cos30 - sin30(x-10)y=sin(x-10-30)y=sin(x-40)所以值域为 -1,1](/uploads/image/z/3849258-66-8.jpg?t=%E6%B1%82%E5%87%BD%E6%95%B0y%3Dsin%28x%2B20%29-cos%28x-10%29%E7%9A%84%E5%80%BC%E5%9F%9Fy%3Dsin%28x%2B20%29-cos%28x-10%29%E7%9A%84%E5%80%BC%E5%9F%9F+%E6%88%91%E8%BF%99%E4%B9%88%E5%81%9A%E5%AF%B9%E5%90%97%EF%BC%9Fy%3Dsin%28x-10%2B30%29+-+cos%28x-10%29y%3Dsin%28x-10%29cos30+%2B+sin30%28x-10%29+-+cos+%28x-10%29y%3Dsin%28x-10%29cos30+-+sin30%28x-10%29y%3Dsin%28x-10-30%29y%3Dsin%28x-40%29%E6%89%80%E4%BB%A5%E5%80%BC%E5%9F%9F%E4%B8%BA+-1%EF%BC%8C1)
求函数y=sin(x+20)-cos(x-10)的值域y=sin(x+20)-cos(x-10)的值域 我这么做对吗?y=sin(x-10+30) - cos(x-10)y=sin(x-10)cos30 + sin30(x-10) - cos (x-10)y=sin(x-10)cos30 - sin30(x-10)y=sin(x-10-30)y=sin(x-40)所以值域为 -1,1
求函数y=sin(x+20)-cos(x-10)的值域
y=sin(x+20)-cos(x-10)的值域 我这么做对吗?
y=sin(x-10+30) - cos(x-10)
y=sin(x-10)cos30 + sin30(x-10) - cos (x-10)
y=sin(x-10)cos30 - sin30(x-10)
y=sin(x-10-30)
y=sin(x-40)
所以值域为 -1,1
求函数y=sin(x+20)-cos(x-10)的值域y=sin(x+20)-cos(x-10)的值域 我这么做对吗?y=sin(x-10+30) - cos(x-10)y=sin(x-10)cos30 + sin30(x-10) - cos (x-10)y=sin(x-10)cos30 - sin30(x-10)y=sin(x-10-30)y=sin(x-40)所以值域为 -1,1
y=sin(x+20)-cos(x-10)
=sin(x+20)-sin[90-(x-10)]
=sin(x+20)-sin(100-x)
=sin(x+20)-sin[180-(100-x)]
=sin(x+20)-sin(x+80)
和差化积
=2cos(x+50)*sin(-30)
=-cos(x+50)
所以值域[-1,1]
y=sin(x+20)-cos(x-10)
x-10=t
y=sin(t+30)-cost=(√3/2)sint-(1/2)cost=-cos(t+60)
值域[-1,1]
[-根号2/2,根号2/2]