Suppose that the functions P and Q are defined as follows.

Question

P(x)= -3x+1

Q(x)= -5x-1

Find the following.

(P×Q)(-4) = ?

(Q×P)(-4) = ?

Answer 1

(P×Q)(x) will simply be the product of the two functions:

15x²-2x-1 which is obtained by multiplying (-3x+1)( -5x-1)

(Q×P)(x_ will be the same thing because multiplication is commutative.

Now put in an x value of -4

(P×Q)(-4)= 15(-4)²-3(-4)-1= 101

(Q×P)(-4)= 15(-4)²-3(-4)-1= 101