Home › CBSE Class 12 (Commerce) › Mathematics › Application of Derivatives › Find the greatest value attained by −x² + 4x + 1.
Find the greatest value attained by −x² + 4x + 1.
A3
B5
C4
D6
Answer & Solution
Correct answer: B. 5
f'(x) = −2x + 4 vanishes at x = 2 and f(2) = −4 + 8 + 1 = 5, a maximum since f'' < 0.
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