Question

Find polynomial (-1)and polynomial (2) for 2x(cube) - 3x +5

Answer 1

Answer:

p(-1) = 6

p(2) = 15

Note:

If the expression of any polynomial p(x) is given the to find the the value of polynomial p(x) at x = a ( ie ; to find p(a) ) , we just need to put x = a everywhere in the expression of p(x) .

Solution:

Here,

The given polynomial is ;

p(x) = 2x³ - 3x + 5 .

We need to find p(-1) and p(2) .

Thus,

=> p(x) = 2x³ - 3x + 5

=> p(-1) = 2(-1)³- 3(-1) + 5

=> p(-1) = -2 + 3 + 5

=> p(-1) = 6

Also,

=> p(x) = 2x³ - 3x + 5

=> p(2) = 2(2)³ - 3(2) + 5

=> p(2) = 16 - 6 + 5

=> p(2) = 15

Hence,

p(-1) = 6

p(2) = 15