14. Let be a basis for R4 and let L : R4 -> R2 be a linear transformation such that


What is the dimension of the kernel of L?

A. 0B. 1 C. 2D. 3 E. 4

Solution The answer is C.

In this case we have, first,

dim(kernel) + dim(range) = 4.

Second, since L maps R4 to R2, the dimension of the range must be less than or equal to 2.

Third, L(e1) and L(e2) are linearly independent, for one is not a multiple of the other, so the dimension of the range space must be at least 2.

Consequently, the dimension of the range space is 2, and the dimension of the kernel is 2.