數學:部分變

p(x)=k1+k2√x k1和k2為非零常數
-1=k1+k2 i
-4=k1+2k2 ii
ii-i
-3=k2
代k2=-3入i
-1=k1-3
k1=2
p(x)=2-3√x
p(9)=2-3*3
p(9)=-7

p(x) = K + A√x

p(1) = K + A = -1

p(4) = K + 2A = -4

A = -3, K = 2

因此p(x) = 2 - 3√ x

代x = 9, p(9) = 2 - 3 * 3 = -7