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Answers to exercises after four compulsory courses in senior high school mathematics
The vector (m 2-n) a+(2n 2+n) b is based on e 1, e2, and the decomposition formula is 2e 1+3e2, a=e 1+e2, b=e 1-e2,

A and b are two nonparallel vectors. Find the values of m and n.

Solution:

(m? -n)a+(2n? +n)b

=(m? -n)(e 1+e2)+(2n? +n)(e 1-e2)

=(m? -n+2n? +n)e 1+(m? -n-2n? -n)e2

=(m? +2n? )e 1+(m? -2n? -2n)e2

=2e 1+3e2

According to the basic theorem of plane vector, we can get

m? +2n? =2

m? -2n? -2n=3

Subtract two expressions: 4n? +2n+ 1=0

Because delta = 2? -4×4 & lt; 0

So there is no solution.