The answer is A,) (-2,-5) because I just did it in my CASIO calculator
(5x³ + 4x²) - (6x² - 2x - 9)
-1(6x²) -1(-2x) -1(-9) = -6x² + 2x + 9
5x³ + 4x² - 6x² + 2x + 9
5x³ - 2x² + 2x + 9 Choice D.
Answer: 120 seconds
Step-by-step explanation: In order to find the maximum value of a function, you can take the derivative of the function and equalize the result to 0.
f'(x)=(-3x^2 + 12x)'=-6x+12=0
x=2
When x is 2, the function will reach its maximum value.
f(2)=-3(2)^2 + 12.2 = -12 + 24 = 12
The maximum value (f(x)) is equal to 12 and the time passed is 2 minutes which is equal to 120 seconds.
