<span>The function can only change from increasing to decreasing, and visa-versa at those points where the slope of the function is 0. And the slope of the function is determined by the first derivative of the function. So let's calculate the first derivative.
f(t) = (t^3 + 3t^2)^3
f'(t) = d/dt[ (t^3 + 3t^2)^3 ]
f'(t) = 3(t^3 + 3t^2)^2 * d/dt[ t^3 + 3t^2 ]
f'(t) = 3(d/dt[ t^3 ] + 3 * d/dt[ t^2 ])(t^3 + 3t^2)^2
f'(t) = 3(3t^2 + 3 * 2t)(t^3 + 3t^2)^2
f'(t) = 3(3t^2 + 6t)(t^3 + 3t^2)^2
Simplify
f'(t) = 3(3t^2 + 6t)(t^3 + 3t^2)^2
f'(t) = 3 * 3t(t + 2)(t^3 + 3t^2)^2
f'(t) = 9t(t + 2)(t^2(t + 3))^2
f'(t) = 9t(t + 2)t^4(t + 3)^2
f'(t) = 9t^5(t + 2)(t + 3)^2
And looking at the function, it becomes obvious that the roots (or inflection points) are at t = 0, t = -2, and t = -3.
Now the only places where f(t) can switch directions is at those 3 inflection points. And at exactly those inflection points the curve is neither increasing, nor decreasing.
If the slope of the function is positive, then its value is increasing, and if the slope is negative, then the function is decreasing. So all we need to do is calculate the value of the first derivative for any value between each inflection point plus one value smaller than the smallest inflection point and another value higher than the highest inflection point.
Range from [-infinity, -3)
f'(-4) = 18432
Since the value is positive, the function is increasing from [-infinity, -3)
Range from (-3, -2)
f'(-2.5) = 30.51758
Since the value is positive, the function is increasing from (-3, -2)
Range from (-2, 0)
f(-1) = -36
Since the value is negative, the function is decreasing from (-2, 0)
Range from (0, infinity)
f(1) = 64
Since the value is positive, the function is increasing from (0, +infinity)
To summarize:
increasing from [-infinity, -3)
increasing from (-3,-2)
decreasing from (-2,0)
increasing from (0,infinity]</span>
Answer:
1.00304 * 10^10
Step-by-step explanation:
The first one dark blue I think
Hi there! So 39,300 copies of a book were sold on debut month of release, and that represents 6.3% of all copies sold to date. To find the total amount of copies sold, we can write and solve a proportion. Set it up like this:
39,300/x = 6.3/100
We set it up like this because 39,300 is part of the total amount, and it represents 6.3% of the total book sales. Percents are parts of 100, which is why 6.3 is above 100. Let's cross multiply the values. 39,300 * 100 is 3,930,000. 6.3 * x is 6.3x. that makes 3,930,000 = 6.3x. Divide each side by 6.3 to isolate the x. 6.3x/6.3 cancels out. 3,930,000/6.3 is 623,809.5238 or 623,810 when rounded to the nearest whole number. There. The total amount of copies sold to date is about 623,810.
Step-by-step explanation:
(1.4 X 10³)³
2.744×10⁹
Hope it helps u
Hey there!
The answer is false. A 90 degree angle is called a right triangle. Any angle less than 90 degree is called an acute angle. Any angle more than 90 degree is called an obtuse angle