Question

NCERT grade 9Factories the following using appropriate identities exercise: 2.4, 3question chapter 2​

Answer 1

ANSWER:

x-1=0

=> x=1

1) P(x)=x^2+x+k

=> P(1)= 1^2+1+k

=> P(1)= 2+k

Since x-1 is a factor of x^2+x+k

2+k= 0

=> k= -2

2) P(x)=2x^2+kx+√2

=> P(1) 2*1^2+k*1+√2

=> P(1) 2+√2+k

Since x-1 is a factor of 2x^2+kx+√2

2+√2+k= 0

=>k= -(2+√2)

3) P(x)=kx^2-√2x+1

=> P(1)= k*1^2-√2*1+1

=> P(1)= k-√2+1

Since x-1 is a factor of kx^2-√2x+1

k-√2+1= 0

=>k= (√2+1)

4) P(x)= kx^2-3x+k

=> P(x)= k*1^2-3*1+k

=> P(x)= k-3+k

=>P(x)= 2k-3

Since x-1 is a factor of kx^2-3x+k

=> 2k-3=0

=> 2k=3

=>k=3/2