Question

4. If x is a real number, find the maximum value of (4 - 6x – x²).​

Answer 1

Answer:

Correct option is

A

13

f(x)=4−6x−x2

For critical points,

f′(x)=0

−6−2x=0

−2x=6

x=−3

For maxima/minima

f′′(x)=−2 (negative)

Hence at x=−3f(x) will have maxima

f(−3)=4−6×(−3)−(−3)2

=4+18−9

f(−3)=13

Maximum value of f(x) is 13

Answer 2

hi mate hope you're doing well here's your answer :)

f(x)=4−6x−x

2

For critical points,

f (x)=0

−6−2x=0

−2x=6

x=−3

For maximum/minimum

f (x)=−2 (negative)

Hence at x=−3f(x) will have maxima

f(−3)=4−6×(−3)−(−3)

2

=4+18−9

f(−3)=13

Maximum value of f

(x) is 13

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