Answer:
That's all you're doing is writing the equation for two lines and finding out where they intersect. The slope is how much the price is increasing or decreasing and the y-intercept is where the price is starting at.
x = number of hours
y = mx + b = 0.12(x + 3) + 15.21 {It's (x + 3) because we have to add the 3 hours between 9 and noon}
y = mx + b = -0.11x + 15.96 {The slope is negative because the price is decreasing}
Set them equal to each other
0.12(x+3) + 15.21 = -0.11x + 15.96
Now solve for x
0.12x + 0.36 + 15.21 = -0.11x + 15.96
0.12x + 15.57 = -0.11x + 15.96
0.12x + 0.11x = 15.96 - 15.57
0.23x = 0.39
x = 0.38 / 0.23 = 1.7 hours
Convert 0.7 into minutes
0.7 hours * (60 min / 1 hour) = 42 min
So the prices are the same 1 hour and 42 min after noon, which is 1:42 PM
Step-by-step explanation:
Answer: =0.8w+2.4
Step-by-step explanation:
Answer:
D.) It has rotational symmetry with an angle of rotation of 90 degrees.
Step-by-step explanation:
i) the shape shown in the figure has reflectional symmetry with four lines of symmetry. There are four lines of symmetry such that each line when drawn divides the shape into two exact halves such that if each half were too be folded across the line of symmetry it would produce the other half exactly.
Therefore Option A.) and Option B.) are not true
ii) It has point symmetry which means if the shape is rotated by 180 degrees the shape does not change. Therefore Option C.) is not true.
iii) the shape has rotational symmetry because if the shape is rotated though any between 0 degrees and 360 degrees the shape appears to be unchanged.
Therefore the correct options are
D.) It has rotational symmetry with an angle of rotation of 90 degrees.
Answer:
80 feet
Step-by-step explanation:
Given:
Initial speed of the car (
) = 40 ft/sec
Deceleration of the car (
) = -10 ft/sec²
Final speed of the car (
) = 0 ft/sec
Let the distance traveled by the car be 'x' at any time 't'. Let 'v' be the velocity at any time 't'.
Now, deceleration means rate of decrease of velocity.
So, 
Negative sign means the velocity is decreasing with time.
Now, 
using chain rule of differentiation. Therefore,
Integrating both sides under the limit 40 to 0 for 'v' and 0 to 'x' for 'x'. This gives,
![\int\limits^0_{40} {v} \, dv=\int\limits^x_0 {-10} \, dx\\\\\left [ \frac{v^2}{2} \right ]_{40}^{0}=-10x\\\\-10x=\frac{0}{2}-\frac{1600}{2}\\\\10x=800\\\\x=\frac{800}{10}=80\ ft](https://tex.z-dn.net/?f=%5Cint%5Climits%5E0_%7B40%7D%20%7Bv%7D%20%5C%2C%20dv%3D%5Cint%5Climits%5Ex_0%20%7B-10%7D%20%5C%2C%20dx%5C%5C%5C%5C%5Cleft%20%5B%20%5Cfrac%7Bv%5E2%7D%7B2%7D%20%5Cright%20%5D_%7B40%7D%5E%7B0%7D%3D-10x%5C%5C%5C%5C-10x%3D%5Cfrac%7B0%7D%7B2%7D-%5Cfrac%7B1600%7D%7B2%7D%5C%5C%5C%5C10x%3D800%5C%5C%5C%5Cx%3D%5Cfrac%7B800%7D%7B10%7D%3D80%5C%20ft)
Therefore, the car travels a distance of 80 feet before stopping.
