Answer:
a) Y(x) = {900, x≤30; 900-40(x-30), x>30}
b) T(x) = {900x, x≤30; 2100x-40x², x>30}
c) dT/dx = {900, x≤30; 2100-80x, x>30}
Step-by-step explanation:
a) The problem statement gives the function for x ≤ 30, and gives an example of evaluating the function for x = 35. So, replacing 35 in the example with x gives the function definition for x > 30.

__
b) The yield per acre is the product of the number of trees and the yield per tree:
T(x) = x·Y(x)

__
c) The derivative is ...

_____
The attached graph shows the yield per acre (purple, overlaid by red for x<30), the total yield (black), and the derivative of the total yield (red). You will note the discontinuity in the derivative at x=30, where adding one more tree per acre suddenly makes the rate of change of yield be negative.
Answer:
a) Surface area = 616 cm²
b) Volume = V = 1083 cm³
Step-by-step explanation:
Surface area and volume of a regular triangular pyramid that has a base edge of 16 cm and a slant height of 15 cm
a) Formula for surface area = Base area × 1/2(perimeter × slant height)
Base area = Base edge²
=( 16 cm)² = 256 cm²
Perimeter = Base edge × 3
= 16 cm × 3 = 48 cm
Hence:
Surface Area = 256 cm² + 1/2(48 × 15)
= 256 cm² + 360 cm²
= 616 cm²
b) Volume = 1/3 × Base area × Height
1082.758616785cm³
Approximately = 1083 cm³
Answer:
3.6 hours
Step-by-step explanation:
The computation of the number of hours will the battery last is given below:
Given that
The capacity of her battery is 2 by 5
And, it declines 1 by 9 for every hour
So,

= 3.6 hours
In the case above, the length of Angle DA is 6 and angle ABD ≈ Angle CAD.
<h3>What is the angle about?</h3>
Note that:
Δ ABC , A = 90
To find length of DA :
Let Δ ACB = x
So Δ ABC = 90 -x
For Δ ABC and ADC:
Δ ADB = Δ ADC (90°)
Δ ABD = Δ DAC (90 - x)
For Δ ABC ≈ ADC:

AD² = BD. CD.
AD²= 9 . 4
AD²= 36
AD = 6
Therefore, In the case above, the length of Angle DA is 6 and angle ABD ≈ Angle CAD.
Learn more about triangle from
brainly.com/question/17335144
#SPJ1
Answer:
7 and 1/4 or 7.25
Step-by-step explanation:
28/4 = 7
1/4 = 0.25
7 + 0.25 = 7.25