作业帮已知二次函数y=a(x+2)^2+3/2的图像与x轴的交点为p1,p2,且|p1p2|=6,求a的值不是很会求出交点,交点p1(-2+根号下-3/2a,0) p2(-2-根号下-3/2a,0)a=-1/6
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已知二次函数y=a(x+2)^2+3/2的图像与x轴的交点为p1,p2,且|p1p2|=6,求a的值不是很会求出交点,交点p1(-2+根号下-3/2a,0) p2(-2-根号下-3/2a,0)a=-1/6
已知二次函数y=a(x+2)^2+3/2的图像与x轴的交点为p1,p2,且|p1p2|=6,求a的值
不是很会求出交点,
交点p1(-2+根号下-3/2a,0) p2(-2-根号下-3/2a,0)
a=-1/6
已知二次函数y=a(x+2)^2+3/2的图像与x轴的交点为p1,p2,且|p1p2|=6,求a的值不是很会求出交点,交点p1(-2+根号下-3/2a,0) p2(-2-根号下-3/2a,0)a=-1/6
不用啊
y=ax²+4ax+4a+3/2
由韦达定理
x1+x2=-4
x1x2=4a+3/2
|P1P2|²=(x1-x2)²
=(x1+x2)²-4x1x2
=16-16a-6
=6²
16a=-26
a=-13/8
y=3cos(2x-7π/4)
=3cos(7π/4-2x)
=3sin[π/2-(7π/4-2x)]
=3sin(2x-5π/4)
=3sin[2(x-5π/8)]
这样是向右移5π/8
y=3cos(2x-7π/4)
=3sin[π/2-(2x-7π/4)]
=3sin(-2x+9π/4)
=3sin(-2x+π/4+2π...
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y=3cos(2x-7π/4)
=3cos(7π/4-2x)
=3sin[π/2-(7π/4-2x)]
=3sin(2x-5π/4)
=3sin[2(x-5π/8)]
这样是向右移5π/8
y=3cos(2x-7π/4)
=3sin[π/2-(2x-7π/4)]
=3sin(-2x+9π/4)
=3sin(-2x+π/4+2π)
=3sin(-2x+π/4)
=3sin[π-(-2x+π/4)]
=3sin(2x+3π/4)
=3sin[2(x+3π/8)]
这样是向左3π/8
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