Asked by Keisha Mitchell
Find the intervals of increase and decrease algebraically for:
Y = −4x³+15x²+ 18x + 3
Y = −4x³+15x²+ 18x + 3
Answers
Answered by
Reiny
The function is increasing when the first derivative is positive, and
it is decreasing .... negative
dy/dx = -12x^2 + 30x + 18
consider the graph of y = -12x^2 + 30x +18
it is a parabola opening down with x-intercepts at x = 3 and x = -1/2
So the function is
increasing for -1/2 < x < 3
decreasing for x<-1/2 or x > 3
confirmation:https://www.wolframalpha.com/input/?i=+y+%3D+%E2%88%924x%5E3%2B15x%5E2+%2B+18x+%2B+3+from+-2+to+6
it is decreasing .... negative
dy/dx = -12x^2 + 30x + 18
consider the graph of y = -12x^2 + 30x +18
it is a parabola opening down with x-intercepts at x = 3 and x = -1/2
So the function is
increasing for -1/2 < x < 3
decreasing for x<-1/2 or x > 3
confirmation:https://www.wolframalpha.com/input/?i=+y+%3D+%E2%88%924x%5E3%2B15x%5E2+%2B+18x+%2B+3+from+-2+to+6
Answered by
Keisha Mitchell
Thank you
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.