解答
x9+x6=36
解答
x=33,x=−3321+3323i,x=−3321−3323i,x=3263cos(3−arctan(2)+π)+3263isin(3−arctan(2)+π),x=3263cos(3−arctan(2)+3π)+3263isin(3−arctan(2)+3π),x=3263cos(3−arctan(2)+5π)+3263isin(3−arctan(2)+5π),x=3263cos(3arctan(2)−π)+3263isin(3arctan(2)−π),x=3263cos(3arctan(2)+π)+3263isin(3arctan(2)+π),x=3263cos(3arctan(2)+3π)+3263isin(3arctan(2)+3π)
求解步骤
x9+x6=36
将 36para o lado esquerdo
x9+x6−36=0
用u=x3,u2=x6 和 u3=x9改写方程式u3+u2−36=0
解 u3+u2−36=0:u=3,u=−2+22i,u=−2−22i
u=3,u=−2+22i,u=−2−22i
代回 u=x3,求解 x
解 x3=3:x=33,x=−3321+3323i,x=−3321−3323i
解 x3=−2+22i:x=3263cos(3−arctan(2)+π)+3263isin(3−arctan(2)+π),x=3263cos(3−arctan(2)+3π)+3263isin(3−arctan(2)+3π),x=3263cos(3−arctan(2)+5π)+3263isin(3−arctan(2)+5π)
解 x3=−2−22i:x=3263cos(3arctan(2)−π)+3263isin(3arctan(2)−π),x=3263cos(3arctan(2)+π)+3263isin(3arctan(2)+π),x=3263cos(3arctan(2)+3π)+3263isin(3arctan(2)+3π)
解为
x=33,x=−3321+3323i,x=−3321−3323i,x=3263cos(3−arctan(2)+π)+3263isin(3−arctan(2)+π),x=3263cos(3−arctan(2)+3π)+3263isin(3−arctan(2)+3π),x=3263cos(3−arctan(2)+5π)+3263isin(3−arctan(2)+5π),x=3263cos(3arctan(2)−π)+3263isin(3arctan(2)−π),x=3263cos(3arctan(2)+π)+3263isin(3arctan(2)+π),x=3263cos(3arctan(2)+3π)+3263isin(3arctan(2)+3π)