Q11 of 168 Page 231

It is given that at x = 1, the function x4 – 62x2 + ax + 9 attains its maximum value, on the interval [0, 2]. Find the value of a.

It is given that f(x) = x4 – 62x2 + ax + 9

Then, f’(x) = 4x3 – 124x+ a


It is given that function f attains its maximum value on the interval [0, 2] at x = 1.


⇒ f’(1) = 0


⇒ 4 – 124 + a = 0


⇒ a = 120


Therefore, the value of a is 120.


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