Question

answer this question correctly and I will mark him brainliest​

Answer 1

Answer:

Answer : Given : f(x) = x3 - 6x2 +9x +15

To find : the interval in which f(x) is increasing or decreasing

Now

f(x) = x3 - 6x2 +9x +15

f `(x) = 3x2 - 12x + 9 = 3 (x2 - 4x + 3 )

for f(x) to increase

f `(x) > 0

=> 3 (x2 - 4x + 3 ) > 0

=> x2 - 4x + 3 > 0

=> (x - 3) ( x - 1) >