Q2 of 82 Page 121

By calculating the following polynomials f(x) let us write the values of f(1) and f(–1):

f(x) = 2x3 + x2 + x + 4

Formula used/Theory.


Putting the value of ‘x’ in f(x) gives out the value of f(x) on ‘x’


We have,


f(x) = 2x3 + x2 + x + 4


When we put x = 1


Then,


f(1) = 2(1)3 + (1)2 + 1 + 4


f(1) = 2+1+1+4


f(1) = 8


When we put x = –1


Then,


f(-1) = 2(-1)3 + (-1)2 + (-1) + 4


f(-1) = (-2) +1–1+4


f(-1) = 2


Conclusion.


The value of f(1), f(-1) are 8, 2 respectively.


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(i) x2 + 3x + 2


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(iii) y2 – 4ax


(iv) x + y + 2


(v) x8 + y4 + x5y9


(vi)

1

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By calculating the following polynomials f(x) let us write the values of f(1) and f(–1):

f(x) = 4 + 3x – x3 + 5x6