Question

Use remainder theorem to find the value of k, it being given that when x^3+2x^2+kx+3 is divided by (x-3), then the remainder is 21​

Answer 1

Answer:

Value of "k" = (-9)

Step-by-step explanation:

Let p(x) = x³+2x²+kx+3                        

     g(x) = (x-3)

Zero of g(x) => (x-3) = 0                           => x = 3

p(3) = (3)³+2(3)²+k(3)+3 = 27+2(9)+3k+3 = 27+18+3k+3 = 48+3k

• As it is given that the remainder obtained when p(x) is divided by g(x) = 21

=> p(3) = 21

=> 48+3k = 21

=> 3k = (-27)

=> k = (-9)

So, The value of "k" = (-9)