Question

C) Let A = (5 2) find the determinant of f(A) such that
f(x) = 2x2 - 6x – 10
​

Answer 1

A=-2 and f(A)=10

Explanation:

therefore

now evaluate

Answer 2

A=-2 and f(A)=10

Explanation:

`det\left[\begin{array}{cc}a&b\\c&d\end{array}\right] =ac-bd`

therefore

`det\left[\begin{array}{cc}1&2\\3&4\end{array}\right] =(1)(4)-(2)(3)=4-6=-2`

now evaluate
`f(-2)`

`f(x)=2x^2-6x-10`

`f(-2)=2(-2)^2-6(-2)-10`

`f(-2)=2(4)+12-10`

`f(-2)=8+2`

`f(-2)=10`