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If the function f(x)=2x3+9x2+12x−1f(x) = 2x^3 + 9x^2 + 12x-1 is given,then f(x)f(x) have

Solution

✅ Correct Option: 1

Given f(x)=2x3+9x2+12x−1f(x) = 2x^3 + 9x^2 + 12x - 1

To find critical points, take the first derivative and set it equal to zero:

f′(x)=6x2+18x+12f'(x) = 6x^2 + 18x + 12

Setting f′(x)=0f'(x) = 0:

6x2+18x+12=06x^2 + 18x + 12 = 0

x2+3x+2=0x^2 + 3x + 2 = 0

(x+1)(x+2)=0(x + 1)(x + 2) = 0

Critical points: x=−1x = -1 and x=−2x = -2


To determine the nature of each critical point, use the second derivative test:

f′′(x)=12x+18f''(x) = 12x + 18

When f′′(x)>0f''(x) > 0, the function has a local minimum.

When f′′(x)<0f''(x) < 0, the function has a local maximum.


At x=−1x = -1:

f′′(−1)=12(−1)+18f''(-1) = 12(-1) + 18

f′′(−1)=−12+18f''(-1) = -12 + 18

f′′(−1)=6>0f''(-1) = 6 > 0

Therefore, f(x)f(x) has a local minimum at x=−1x = -1.


At x=−2x = -2:

f′′(−2)=12(−2)+18f''(-2) = 12(-2) + 18

f′′(−2)=−24+18f''(-2) = -24 + 18

f′′(−2)=−6<0f''(-2) = -6 < 0

Therefore, f(x)f(x) has a local maximum at x=−2x = -2.


The function f(x)=2x3+9x2+12x−1f(x) = 2x^3 + 9x^2 + 12x - 1 has a local minima at x=−1x = -1 and a local maxima at x=−2x = -2.

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