假设当x = 4时,y与x的平方根成反比,y = 50,当x = 5时,你如何找到y?
如果y与sqrt(x)成反比,则y * sqrt(x)= c对于某些常数c给定(x,y)=(4,50)是这个逆变量的解,那么50 * sqrt(4)= c rarr c = 100 color(white)(“xxxxxxxxxx”)(见下面的注释),逆变化方程为y * sqrt(x)= 100当x = 5时,这变为y * sqrt(5)= 100 sqrt(5) = 100 / y 5 = 10 ^ 4 / y ^ 2 y = sqrt(5000)= 50sqrt(2)注:我已解释“y与x的平方根成反比”是指x的正平方根(即sqrt(x))这也暗示y是正数。如果这不是预期的情况,则还需要允许y的否定版本。
假设x作为y和z共同变化。如果当y = 2且z = 4时x = 50,当y = 6且z = 10时,如何找到x?
关节变化意味着:x(y,z)= kyz。请参阅解决方案的说明。给定:x(y,z)= kyz且x(2,4)= 50 50 = k(2)(4)k = 25/4 x(6,10)= 25/4(6)(10)= 375 larr答案
如果y直接变化为x,如果x = -6,当y = 2时,当y = -9,-8,-6,-5,-4,-3时,如何找到x?
Y = -9 rarr x = -17 y = -8 rarr x = -16 y = -6 rarr x = -14 y = -5 rarr x = -13 y = -4 rarr x = -12 y = -3 rarr x = -11如果y直接变为x,那么当x增加或减少数n时,y也是如此。如果当x = -6时y = 2则:y = -9 = 2-11 rarr x = -6-11 = -17 y = -8 = 2-10 rarr x = -6-10 = -16 y = - 6 = 2-8 rarr x = -6-8 = -14 y = -5 = 2-7 rarr x = -6-7 = -13 y = -4 = 2-6 rarr x = -6-6 = - 12 y = -3 = 2-5 rarr x = -6-5 = -11